Parasiticidal compositions comprising eprinomectin and praziquantel, methods and uses thereof

ABSTRACT

This invention relates to compositions for combating ectoparasites and endoparasites in animals, comprising eprinomectin and praziquantel in combination with a pharmaceutically acceptable carrier, and optionally an antioxidant. This invention also provides for an improved methods for eradicating, controlling, and preventing parasite infections and infestations in an animal comprising administering the compositions of the invention to the animal in need thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalApplication No. 62/627,978, filed Feb. 8, 2018, and U.S. ProvisionalApplication No. 62/697,576, filed Jul. 13, 2018, both of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention provides veterinary compositions having a stable,extended shelf-life, the compositions comprise at least one macrocycliclactone active agent and at least one anthelmintic active agent forcontrolling ectoparasites and endoparasites in animals; the use of thesecompositions against ectoparasites and/or endoparasites, and methods forpreventing or treating parasitic infections and infestations in animals.

BACKGROUND OF THE INVENTION

Animals such as mammals and birds are often susceptible to parasiteinfestations/infections. These parasites may be ectoparasites, such asinsects, and endoparasites such as filariae and other worms.Domesticated animals, such as cats and dogs, are often infested with oneor more of the following ectoparasites:

-   -   fleas (e.g. Ctenocephalides spp., such as Ctenocephalides felis        and the like),    -   ticks (e.g. Rhipicephalus spp., Ixodes spp., Dermacentor spp.,        Amblyoma spp., and the like),    -   mites (e.g. Demodex spp., Sarcoptes spp., Otodectes spp., and        the like),    -   lice (e.g. Trichodectes spp., Cheyletiella spp., Lignonathus        spp. and the like),    -   mosquitoes (Aedes spp., Culux spp., Anopheles spp. and the like)        and    -   flies (Hematobia spp., Musca spp., Stomoxys spp., Dematobia        spp., Coclyomia spp. and the like).

Fleas are a particular problem because not only do they adversely affectthe health of the animal or human, but they also cause a great deal ofpsychological stress. Moreover, fleas are also vectors of pathogenicagents in animals and humans, such as dog tapeworm (Dipylidium caninum).

Similarly, ticks are also harmful to the physical and psychologicalhealth of the animal or human. However, the most serious problemassociated with ticks is that they are the vector of pathogenic agentsin both humans and animals. Major diseases which are caused by ticksinclude borrelioses (Lyme disease caused by Borrelia burgdorferi),babesioses (or piroplasmoses caused by Babesia spp.) and rickettsioses(also known as Rocky Mountain spotted fever). Ticks also release toxinswhich cause inflammation or paralysis in the host. Occasionally, thesetoxins are fatal to the host.

Likewise, farm animals are also susceptible to parasite infestations.For example, cattle are affected by a large number of parasites. Aparasite which is very prevalent among farm animals is the tick genusBoophilus, especially those of the species microplus (cattle tick),decoloratus and annulatus. Ticks, such as Boophilus microplus, areparticularly difficult to control because they live in the pasture wherefarm animals graze.

Animals and humans also suffer from endoparasitical infectionsincluding, for example, helminthiasis which is most frequently caused bya group of parasitic worms categorized as cestodes (tapeworm), nematodes(roundworm) and trematodes (flatworm or flukes). These parasitesadversely affect the nutrition of the animal and cause severe economiclosses in pigs, sheep, horses, and cattle as well as affecting domesticanimals and poultry. Other parasites which occur in the gastrointestinaltract of animals and humans include Ancylostoma, Necator, Ascaris,Strongyloides, Trichinella, Capillaria, Toxocara, Toxascaris, Trichiris,Enterobius and parasites which are found in the blood or other tissuesand organs such as filarial worms and the extra intestinal stages ofStrogyloides, Toxocara and Trichinella

Milbemycin or avermectin derivatives are natural or semi-syntheticcompounds that contain a 16-membered macrocyclic ring. The avermectinand milbemycin series of compounds are potent anthelmintic andantiparasitic agents against a wide range of internal and externalparasites. The natural product avermectins are disclosed in U.S. Pat.No. 4,310,519 to Albers-Schonberg, et al., and the 22,23-dihydro-avermectin compounds are disclosed in Chabala, et al., U.S.Pat. No. 4,199,569. For a general discussion of avermectins, whichinclude a discussion of their uses in humans and animals, see“Ivermectin and Abamectin,” W. C. Campbell, ed., Springer-Verlag, NewYork (1989). Naturally occurring milbemycins are described in Aoki etal., U.S. Pat. No. 3,950,360.

Eprinomectin is a semi-synthetic compound of the avermectin family andconsists of a mixture of isomeric compounds, isomer B1a(4″-epi-acetylamino-4″-deoxy-avermectin B1a) and isomer B1b(4″-epi-acetylamino-4″-deoxy-avermectin B1b), which differ by a singlemethylene group. The B1a and B1b isomers have the following structures:

Eprinomectin is used for effective control of internal parasites incattle and other ruminant species (deer, goats). In the United States,eprinomectic is approved by the FDA for the use in beef and dairycattle, including lactating dairy cattle (IVOMEC® EPRINEX® Pour-On forBeef and Dairy Cattle).

Eprinomectin, like other avermectins, binds selectively and with highaffinity to glutamate-gated chloride ion channels which occur ininvertebrate nerve and muscle cells. This leads to an increase in thepermeability of the cell membrane to chloride ions withhyperpolarization of the nerve or muscle cell, resulting in paralysisand death of the parasite.

Other pharmaceutical or therapeutic agents are those known in the art totreat parasitic infection caused by nematodes and trematodes. In orderto treat cestode (and trematode) infections in warm-blooded animals, itis known, to administer 2-acyl-4-oxo-pyrazino-isoquinoline derivativesto the animal (see, e.g., U.S. Pat. No. 4,001,441, herein incorporatedby reference). A compound of this class that is often used to treatcestode and nematode infections is praziquantel, which has the followingstructure:

Praziquantel may be used in the treatment of endoparasitic infectionsincluding infections by liver flukes or schistosoma. Praziquantel worksby causing severe spasms and paralysis of the worm's muscles.

U.S. Pat. No. 9,173,403 B1 relates to compositions for combatingectoparasites and endoparasites in animals, comprising at least one1-arypyrazole, at least one macrocyclic lactone, at least one insectgrowth regulator, and at least one anthelmintic compound in combinationwith a pharmaceutically acceptable carrier.

U.S. Pat. No. 6,991,801 B1 provides for topical anthelminticformulations which comprise a pharmaceutically active combinationconsisting of at least one macrocyclic compound and at least onecompound selected from the group consisting of praziquantel, moranteland pyrantel, which are dissolved in a non-aqueous solvent or solventmixture, and optionally a thickening agent.

Notwithstanding the compositions comprising milbemycin or avermectinactive agents alone or in combination with other active agents describedin the documents above, there is a need for veterinary compositions andmethods with improved efficacy and spectrum of coverage and increasedshelf life to protect animals against both endoparasites andectoparasites.

INCORPORATION BY REFERENCE

Any foregoing applications, and all documents cited therein or duringtheir prosecution (“application cited documents”) and all documentscited or referenced in the application cited documents, and alldocuments cited or referenced herein (“herein cited documents”), and alldocuments cited or referenced in herein cited documents, together withany manufacturer's instructions, descriptions, product specifications,and product sheets for any products mentioned herein or in any documentincorporated by reference herein, are hereby incorporated herein byreference, and may be employed in the practice of the invention.

Citation or identification of any document in this application is not anadmission that such document is available as prior art to the presentinvention.

SUMMARY OF THE INVENTION

The present invention provides compositions and formulations comprisingat least one macrocyclic lactone compound in combination with at leastone anthelmintic compound; uses or veterinary uses thereof for thetreatment or prophylaxis of parasitic infections and infestations ofanimals (either wild or domesticated), including livestock and companionanimals such as cats, dogs, horses, chickens, sheep, goats, pigs,turkeys and cattle, with the aim of ridding these hosts of parasitescommonly encountered by such animals. In an embodiments, the topicalveterinary composition of the invention are advantageously in the formof a spot-on or a pour-on formulation for application to localized areason the animal to be treated (e.g. in one spot on the midline of theneck, between the base of the skull and the shoulder blades for spot-onor in line down the back from the shoulders to the tail for pour-on). Inanother embodiment, the topical veterinary composition has a shelf-lifeof at least 6 months, at least 12 months, at least 18 months, at least24 months, at least 36 months, or at least 48 months.

The invention also provides methods for the treatment or prevention ofparasitic infections and infestations in animals, comprisingadministering an effective amount of a composition described herein.Surprisingly, it has been found that the inventive compositions andformulations described herein have a stable, extended shelf-life andexhibit superior broad spectrum efficacy against harmful endoparasitesand/or ectoparasites over a long duration compared to compositions knownin the art.

In one embodiment, the invention provides topical veterinarycompositions having an extended shelf-life comprising effective amountsof at least one macrocyclic lactone active agent and at least oneanthelmintic active agent together with a pharmaceutically orveterinarily acceptable liquid carrier, and optionally an antioxidant,wherein the composition has a shelf-life of at least 6 months, at least12 months, at least 18 months, at least 24 months, at least 36 months,or at least 48 months. In another embodiment, the composition furthercomprises a penetration enhancer, optionally wherein the penetrationenhancer is propylene glycol.

In some embodiments, the macrocyclic lactone active agent is anavermectin or a milbemycin active agent including, but not limited to,eprinomectin, ivermectin, selamectin, milbemectin, milbemycin D,milbemycin oxime, or moxidectin.

In other embodiments, the compositions and methods comprise at least oneof thiabendazole, oxibendazole, mebendazole, fenbendazole, oxfendazole,albendazole, triclabendazole, febantel, levamisole, pyrantel, morantel,praziquantel, closantel, clorsulon, an amino acetonitrile active agent,or an aryloazol-2-yl cyanoethylamino active agent.

In some embodiments, the topical veterinary composition of the inventionmay comprise a C₁-C₁₀ alcohol or ester, a C₁₀-C₁₈ saturated fatty acidor esters, a C₁₀-C₁₈ monounsaturated fatty acid or ester, a monoester ordiester of an aliphatic diacid, a glycerol monoesters, a glyceroldiester, a glycerol triester, a glycol, a glycol ether, a glycol ester,a glycol carbonate, a polyethylene glycol, a polyethylene glycolmonoether, a polyethylene glycol diether, a polyethylene glycolmonoester, a polyethylene glycol diester, or a mixture thereof ascomponents in the pharmaceutically or veterinarily acceptable carrier ordiluent. In other embodiments, the compositions may include acetone,acetonitrile, benzyl alcohol, ethanol, isopropanol, diisobutyl adipate,diisopropyl adipate, glycerol formal, butyl diglycol, dipropylene glycoln-butyl ether, ethylene glycol monoethyl ether, ethylene glycolmonomethyl ether, dipropylene glycol monomethyl ether, liquidpolyoxyethylene glycols, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, dimethyl isosorbide, 2-pyrrolidone,N-methylpyrrolidone, diethylene glycol monoethyl ether, triacetin, butylacetate, octyl acetate, propylene carbonate, butylene carbonate,dimethyl sulfoxide, dimethylformamide, dimethylacetamide, or anycombination thereof in the pharmaceutically or veterinarily acceptablecarrier or diluent. In other embodiments, the topical veterinaycomposition of the invention comprises glycerol formal and dimethylisosorbide (DMI). In an embodiment, the glycerol formal is unstabilizeddue to the absence of stabilizers. In another embodiment, the glycerolformal is unstabilized due to the absence of ethylenediaminetetraaceticacid (EDTA). In another embodiment, the glycerol formal is unstabilizeddue to the absence of 2,6-di-tert-butyl-4-methyl phenol.

In some embodiments, the topical veterinary composition of the inventioncomprises an antioxidant. In other embodiments, the antioxidant isbutylated hydroxytoluene (BHT) or butylated hydroxyanisole (BHA).

In an embodiment, the macrocyclic lactone active agent compriseseprinomectin. In another embodiment, the anthelmintic active agentcomprises praziquantel.

The present invention provides a topical veterinary composition having astable, extended shelf-life, the composition comprises about 0.01% (w/v)to about 10% (w/v) eprinomectin, about 1.0% (w/v) to about 30.0% (w/v)praziquantel, about 20% (w/s) to about 35.0% (w/v) unstabilized glycerolformal, about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, andabout 0.01% (w/v) to about 2.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists essentially of about0.01% (w/v) to about 10% (w/v) eprinomectin, about 1.0% (w/v) to about30.0% (w/v) praziquantel, about 20% (w/s) to about 35.0% (w/v)unstabilized glycerol formal, about 50.0% (w/v) to about 75.0% (w/v)dimethyl isosorbide, and about 0.01% (w/v) to about 2.0% (w/v) butylatedhydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists essentially of about0.1% (w/v) to about 5.0% (w/v) eprinomectin, about 5.0% (w/v) to about15.0% (w/v) praziquantel, about 25% (w/s) to about 35.0% (w/v)unstabilized glycerol formal, about 55.0% (w/v) to about 65.0% (w/v)dimethyl isosorbide, and about 0.01% (w/v) to about 1.0% (w/v) butylatedhydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists essentially of about0.1% (w/v) to about 1.0% (w/v) eprinomectin, about 8.0% (w/v) to about12.0% (w/v) praziquantel, about 25% (w/s) to about 35.0% (w/v)unstabilized glycerol formal, about 55.0% (w/v) to about 65.0% (w/v)dimethyl isosorbide, and about 0.01% (w/v) to about 1.0% (w/v) butylatedhydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists essentially of about0.40% (w/v) eprinomectin, about 8.30% (w/v) praziquantel, about 0.10%(w/v) butylated hydroxytoluene, about 30.38% (w/v) unstabilized glycerolformal, and QS dimethyl isosorbide.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists of about 0.01% (w/v) toabout 10% (w/v) eprinomectin, about 1.0% (w/v) to about 30.0% (w/v)praziquantel, about 20% (w/s) to about 35.0% (w/v) unstabilized glycerolformal, about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, andabout 0.01% (w/v) to about 2.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists of about 0.1% (w/v) toabout 5.0% (w/v) eprinomectin, about 5.0% (w/v) to about 15.0% (w/v)praziquantel, about 25% (w/s) to about 35.0% (w/v) unstabilized glycerolformal, about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide, andabout 0.01% (w/v) to about 1.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists of about 0.1% (w/v) toabout 1.0% (w/v) eprinomectin, about 8.0% (w/v) to about 12.0% (w/v)praziquantel, about 25% (w/s) to about 35.0% (w/v) unstabilized glycerolformal, about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide, andabout 0.01% (w/v) to about 1.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition havingan extended shelf-life, the composition consists of about 0.40% (w/v)eprinomectin, about 8.30% (w/v) praziquantel, about 0.10% (w/v)butylated hydroxytoluene, about 30.38% (w/v) unstabilized glycerolformal, and QS dimethyl isosorbide.

In some embodiment, the topical veterinary composition having anextended shelf-life of the present invention is in the form of a spot-onor a pour-on formulation.

The present invention provides a method for the treatment or preventionof a parasitic infestation or infection in an animal comprisingadministering to the animal in need thereof an effective amount of anyof the topical veterinary compositions described herein. In someembodiment, the parasite is an ectoparasite or an endoparasite.

It is an object of the invention to not encompass within the inventionany previously known product, process of making the product, or methodof using the product such that the Applicants reserve the right andhereby disclose a disclaimer of any previously known product, process,or method. It is further noted that the invention does not intend toencompass within the scope of the invention any product, process, ormaking of the product or method of using the product, which does notmeet the written description and enablement requirements of the USPTO(35 U.S.C. § 112, first paragraph) or the EPO (Article 83 of the EPC),such that Applicants reserve the right and hereby disclose a disclaimerof any previously described product, process of making the product, ormethod of using the product.

These and other embodiments are disclosed or are obvious from andencompassed by, the following Detailed Description.

BRIEF DESCRIPTION OF THE FIGURES

The following detailed description, given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a plot showing the concentration (ng/mL) of eprinomectin andpraziquantel in the blood of cats over time (days) after administrationof the formulation in Example 1 to cats.

DETAILED DESCRIPTION

The present invention provides novel and inventive compositionscomprising at least one macrocyclic lactone compound in combination withat least one anthelmintic compound together with a pharmaceuticallyacceptable carrier or diluent, optionally an antioxidant. In someembodiments, the compositions further comprise a penetration enhancer.

The compositions of the present invention have an extended shelf-life,e.g., at least 6 months, at least 12 months, at least 18 months, atleast 24 months, at least 36 months, or at least 48 months.

The compositions of the invention can be in a variety of forms suitablefor different forms of administration including, but are not limited to,oral formulations, injectable formulations, and topical, dermal orsubdermal formulations.

In some embodiments of the invention, the compositions are in a formthat is suitable for topical administration, which includes spot-onformulations that are applied to a localized area on an animal. Topicalpour-on formulations are also encompassed by the invention. Theseformulations provide surprisingly effective protection of the animalsagainst endoparasites for an extended period of time.

In one aspect, the invention provides topical compositions comprising atleast one macrocyclic lactone compound in combination with at least oneanthelmintic compound together with a pharmaceutically acceptablecarrier or diluent, optionally an antioxidant and/or a penetrationenhancer.

In one embodiment, the compositions of the invention comprise at leastone avermectin or milbemycin compound. In another embodiment, the atleast one avermectin or milbemycin compound included in the compositionsis abamectin, dimadectin, doramectin, emamectin, eprinomectin,ivermectin, latidectin, lepimectin, selamectin, milbemectin, milbemycinD, moxidectin or nemadectin. In yet another embodiment, the compositionsof the invention comprise eprinomectin.

In one embodiment, the compositions of the invention comprise at leastone anthelmintic compound. In another embodiment, the compositions ofthe invention comprise praziquantel.

Also provided are methods and uses for the treatment and/or prophylaxisof parasitic infections and infestations of animals, comprisingadministering an effective amount of a formulation of the inventiondescribed herein to the animal.

The invention includes at least the following features:

(a) The invention provides novel compositions having a stable, extendedshelf-life that exhibit superior activity against animal parasitescomprising at least one macrocyclic lactone compound in combination withat least one anthelmintic active agent, or pharmaceutically acceptablesalts, solvates or hydrates thereof, together with a pharmaceuticallyacceptable carrier or diluent, and optionally an antioxidant;

(b) topical veterinary formulations having a stable, extended shelf-lifethat exhibit superior activity against animal parasites comprising atleast one macrocyclic lactone active agent in combination with at leastone anthelmintic compound, or pharmaceutically acceptable salts,solvates or hydrates thereof, together with a pharmaceuticallyacceptable carrier or diluent, and optionally an antioxidant;

(c) veterinary compositions having a stable, extended shelf-lifecomprising eprinomectin in combination with at least one anthelminticcompound, or pharmaceutically acceptable salts, solvates or hydratesthereof, and a pharmaceutically acceptable carrier or diluent, andoptionally an antioxidant;

(d) veterinary compositions having a stable, extended shelf-lifecomprising or consisting essential of eprinomectin in combination withpraziquantel, or pharmaceutically acceptable salts, solvates or hydratesthereof, and a pharmaceutically acceptable carrier or diluent, andoptionally an antioxidant;

(e) topical spot-on veterinary formulations having a stable, extendedshelf-life, consisting essentially of eprinomectin and at least oneanthelmintic compound, or pharmaceutically acceptable salts, solvates orhydrates thereof, and a pharmaceutically acceptable carrier or diluent,and optionally an antioxidant;

(f) methods for the treatment or prevention of parasitic infections andinfestations in an animal comprising administering an effective amountof a composition having a stable, extended shelf-life, the compositioncomprises at least one macrocyclic lactone active agent in combinationwith at least one anthelmintic active agent, or pharmaceuticallyacceptable salts, solvates or hydrates thereof, together with apharmaceutically acceptable carrier or diluent, and optionally anantioxidant;

(g) methods for the treatment or prevention of parasitic infections andinfestations in an animal comprising administering an effective amountof a composition having a stable, extended shelf-life, the compositioncomprises, consists essentially of, or consists of eprinomectin incombination with praziquantel, or pharmaceutically acceptable salts,solvates or hydrates thereof, together with a pharmaceuticallyacceptable carrier or diluent, and optionally an antioxidant;

(h) use of veterinary compositions having a stable, extended shelf-life,the compositions comprise at least one macrocyclic lactone active agentin combination with at least one anthelmintic compound, orpharmaceutically acceptable salts, solvates or hydrates thereof,together with a pharmaceutically acceptable carrier or diluent in theprevention or treatment of animal parasites;

(i) use of veterinary compositions having a stable, extended shelf-life,the compositions comprise, consist essentially of, or consist ofeprinomectin in combination with praziquantel, or pharmaceuticallyacceptable salts, solvates or hydrates thereof, together with apharmaceutically acceptable carrier or diluent, and optionally anantioxidant.

In this disclosure and in the claims, terms such as “comprises,”“comprising,” “containing” and “having” and the like can have themeaning ascribed to them in U.S. patent law and can mean “includes,”“including,” and the like; “consisting essentially of” or “consistsessentially” likewise has the meaning ascribed in U.S. patent law andthe term is open-ended, allowing for the presence of more than thatwhich is recited so long as basic or novel characteristics of that whichis recited is not changed by the presence of more than that which isrecited, but excludes prior art embodiments; and “consist of” likewisehas the meaning ascribed in U.S. patent law and excludes any element,step, or ingredient not specified in the claim.

It is also noted that in this disclosure and in the claims and/orparagraphs, the compounds of the invention are intended to include allstereoisomers and crystalline forms (which includes hydrated forms,polymorphic forms and amorphous forms with up to 15% by weightcrystalline structure) thereof.

Definitions

Terms used herein will have their customary meaning in the art unlessspecified otherwise. The organic moieties mentioned in the definitionsof the variables of formula (I) or (IA) are—like the termhalogen—collective terms for individual listings of the individual groupmembers. The prefix C_(n)-C_(m) indicates in each case the possiblenumber of carbon atoms in the group.

The term “animal” is used herein to include all mammals, birds and fishand also include all vertebrate animals, including humans. Animalsinclude, but are not limited to, humans, cats, dogs, cattle, chickens,cows, deer, goats, horses, llamas, pigs, sheep and yaks. It alsoincludes an individual animal in all stages of development, includingembryonic and fetal stages.

The term “effective amount” as used herein means a concentration of theactive agents in the composition sufficient to elicit the desiredbiological response to the target parasite(s) after administration ofthe composition to the animal, as measured by methods known in the artand/or described in the examples herein. In some embodiments, an“effective amount” of the active agents in the composition will providean efficacy of at least 70% against the target parasite compared to anuntreated control. In other embodiments, “an effective amount” of theactive agent will provide an efficacy of at least 80%, or at least 85%compared to untreated controls. More typically, “an effective amount” ofthe active agents will provide an efficacy of at least 90%, at least93%, at least 95% or at least 97% against the target parasite.

In a specific embodiment, the term “about” or “approximately” meanswithin 20%, preferably within 10%, and more preferably within 5% of agiven value or range.

Stereoisomers and Polymorphic Forms

It will be appreciated by those of skill in the art that certaincompounds within the compositions of the invention may exist and beisolated as optically active and racemic forms. Compounds having one ormore chiral centers, including at a sulfur atom, may be present assingle enantiomers or diastereomers or as mixtures of enantiomers and/ordiastereomers. For example, it is well known in the art that sulfoxidecompounds may be optically active and may exist as single enantiomers orracemic mixtures. In addition, compounds within the compositions of theinvention may include one or more chiral centers, which results in atheoretical number of optically active isomers. Where compounds withinthe compositions of the invention include n chiral centers, thecompounds may comprise up to 2^(n) optical isomers. The presentinvention encompasses the specific enantiomers or diastereomers of eachcompound as well as mixtures of different enantiomers and/ordiastereomers of the compounds of the invention that possess the usefulproperties described herein. The optically active forms can be preparedby, for example, resolution of the racemic forms by selectivecrystallization techniques, by synthesis from optically activeprecursors, by chiral synthesis, by chromatographic separation using achiral stationary phase or by enzymatic resolution.

The compounds within the compositions of present invention may also bepresent in different solid forms such as different crystalline forms orin the form of an amorphous solid. The present invention encompassesdifferent crystalline forms as well as amorphous forms of the inventivecompounds.

In addition, the compounds within the compositions of the invention mayexist as hydrates or solvates, in which a certain stoichiometric amountof water or a solvent is associated with the molecule in the crystallineform. The compositions of the invention may include hydrates andsolvates of the active agents.

Salts

Also contemplated within the scope of the invention are acid or basesalts, where applicable, of the compounds of the invention provided forherein.

The term “acid” contemplates all pharmaceutically acceptable inorganicor organic acids. Inorganic acids include mineral acids such ashydrohalic acids such as hydrobromic acid and hydrochloric acid,sulfuric acid, phosphoric acids and nitric acid. Organic acids includeall pharmaceutically acceptable aliphatic, alicyclic and aromaticcarboxylic acids, dicarboxylic acids, tricarboxylic acids and fattyacids. In one embodiment of the acids, the acids are straight chain orbranched, saturated or unsaturated C₁-C₂₀ aliphatic carboxylic acids,which are optionally substituted by halogen or by hydroxyl groups, orC₆-C₁₂ aromatic carboxylic acids. Examples of such acids are carbonicacid, formic acid, acetic acid, propionic acid, isopropionic acid,valeric acid, α-hydroxy acids such as glycolic acid and lactic acid,chloroacetic acid, benzoic acid, methane sulfonic acid, and salicylicacid. Examples of dicarboxylic acids include oxalic acid, malic acid,succinic acid, tartaric acid, fumaric acid, and maleic acid. An exampleof a tricarboxylic acid is citric acid. Fatty acids include allpharmaceutically acceptable saturated or unsaturated aliphatic oraromatic carboxylic acids having 4 to 24 carbon atoms. Examples includebutyric acid, isobutyric acid, sec-butyric acid, lauric acid, palmiticacid, stearic acid, oleic acid, linoleic acid, linolenic acid, andphenylsteric acid. Other acids include gluconic acid, glycoheptonic acidand lactobionic acid.

The term “base” contemplates all pharmaceutically acceptable inorganicor organic bases, including hydroxides, carbonates or bicarbonates ofalkali metal or alkaline earth metals. Salts formed with such basesinclude, for example, the alkali metal and alkaline earth metal salts,including, but not limited to, as the lithium, sodium, potassium,magnesium or calcium salts. Salts formed with organic bases include thecommon hydrocarbon and heterocyclic amine salts, which include, forexample, ammonium salts (NH4⁺), alkyl- and dialkylammonium salts, andsalts of cyclic amines such as the morpholine and piperidine salts.

In one embodiment, the invention provides compositions that comprise atleast one macrocyclic lactone active agent in combination with at leastone anthelmintic compound, or pharmaceutically acceptable salts,hydrates or solvates thereof, together with a pharmaceuticallyacceptable carrier or diluent, and optionally an antioxidant and/or apenetration enhancer.

In an embodiment, the invention provides compositions (e.g., spot-on,pour-on) having an extended shelf-life for the treatment or preventionof a parasitic infection or infestation in an animal comprising at leastone macrocyclic lactone active agent in combination with at least oneanthelmintic compound together with a pharmaceutically acceptablecarrier, wherein the macrocyclic lactone active agent is eprinomectin.

The macrocyclic lactone compounds are also well known in the art and canbe obtained commercially or through known synthesis techniques. Foravermectins, ivermectin and abamectin, reference may be made, forexample, to the publication “Ivermectin and Abamectin”, 1989, by M. H.Fischer and H. Mrozik, William C. Campbell, published by SpringerVerlag., “Macrocyclic Lactones in Antiparasitic Therapy”, 2002, by JVercruysse and RS Rew published by CABI Publishing or Albers-Schonberget al. (1981), “Avermectins Structure Determination”, J. Am. Chem. Soc.,103, 4216-4221. For doramectin, “Veterinary Parasitology”, vol. 49, No.1, July 1993, 5-15 may be consulted. For milbemycins, reference may bemade, inter alia, to Davies H. G. et al., 1986, “Avermectins andMilbemycins”, Nat. Prod. Rep., 3, 87-121, Mrozik H. et al., 1983,Synthesis of Milbemycins from Avermectins, Tetrahedron Lett., 24,5333-5336, U.S. Pat. No. 4,134,973 and EP 0 677 054, all of which areincorporated herein by reference.

Macrocyclic lactones are either natural products or are semi-syntheticderivatives thereof. The structures of the avermectins and milbemycinsare closely related, e.g., by sharing a complex 16-membered macrocycliclactone ring; milbemycins lack the glycosidic moiety of the avermectins.The natural products avermectins are disclosed in U.S. Pat. No.4,310,519 to Albers-Schonberg et al., and the 22,23-dihydro avermectincompounds are disclosed in Chabala et al., U.S. Pat. No. 4,199,569.Mention is also made of Kitano, U.S. Pat. No. 4,468,390, Beuvry et al.,U.S. Pat. No. 5,824,653, EP 0 007 812 A1, U.K. Patent Specification 1390 336, EP 0 002 916, and Ancare New Zealand Patent No. 237 086, interalia. Naturally occurring milbemycins are described in Aoki et al., U.S.Pat. No. 3,950,360 as well as in the various references cited in “TheMerck Index” 12^(th) ed., S. Budavari, Ed., Merck & Co., Inc. WhitehouseStation, N.J. (1996). Latidectin is described in the “InternationalNonproprietary Names for Pharmaceutical Substances (INN)”, WHO DrugInformation, vol. 17, no. 4, pp. 263-286, (2003). Semisyntheticderivatives of these classes of compounds are well known in the art andare described, for example, in U.S. Pat. Nos. 5,077,308, 4,859,657,4,963,582, 4,855,317, 4,871,719, 4,874,749, 4,427,663, 4,310,519,4,199,569, 5,055,596, 4,973,711, 4,978,677, 4,920,148 and EP 0 667 054,all incorporated herein by reference.

In an embodiment, the compositions having an extended shelf-life of theinvention comprise at least one avermectin or milbemycin compound incombination with at least one anthelmintic active agent. The avermectinand milbemycin active agents include, but are not limited to, abamectin,dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin,lepimectin, selamectin, milbemectin, milbemycin D, milbemycin oxime,moxidectin or nemadectin, or mixtures of these active agents.

Various types of anthelmintic agents (in addition to one or moremacrocyclic lactone) may be used in the compositions of the invention.In some embodiments, the compositions of the invention may include oneor more antinematodal agents including, but not limited to, abenzimidazole, an imidazothiazole, a tetrahydropyrimidine, anorganophosphate active agent, or mixtures of these active agents. Insome embodiments, benzimidazoles including, but not limited to,thiabendazole, cambendazole, parbendazole, oxibendazole, mebendazole,flubendazole, fenbendazole, oxfendazole, albendazole, cyclobendazole,triclabendazole, febantel, thiophanate and its o,o-dimethyl analogue maybe included in the compositions.

In other embodiments, the compositions may include an imidazothiazolecompounds including, but not limited to, tetramisole, levamisole andbutamisole. In still other embodiments, the compositions of theinvention may include tetrahydropyrimidine active agents including, butnot limited to, pyrantel, oxantel, and morantel.

In still other embodiments, the compositions may include theantinematodal compounds phenothiazine, piperazine as the neutralcompound and in various salt forms, diethylcarbamazine, phenols such asdisophenol, arsenicals such as arsenamide, ethanolamines such asbephenium, thenium closylate, and methyridine; cyanine dyes includingpyrvinium chloride, pyrvinium pamoate and dithiazanine iodide;isothiocyanates including bitoscanate, suramin sodium, phthalofyne, andvarious natural products including, but not limited to, hygromycin B,α-santonin and kainic acid.

In other embodiments, the compositions of the invention may includeantitrematodal agents. Suitable antitrematodal agents include, but arenot limited to, the miracils such as miracil D and mirasan;praziquantel, clonazepam and its 3-methyl derivative, oltipraz,lucanthone, hycanthone, oxamniquine, amoscanate, niridazole, nitroxynil,various bisphenol compounds known in the art including hexachlorophene,bithionol, bithionol sulfoxide and menichlopholan; varioussalicylanilide compounds including tribromsalan, oxyclozanide,clioxanide, rafoxanide, brotianide, bromoxanide and closantel;triclabendazole, diamfenetide, clorsulon, hetolin and emetine. In someembodiments, the compositions of the invention comprise praziquantel.

Anticestodal compounds may also be advantageously used in thecompositions of the invention including, but not limited to, arecolinein various salt forms, bunamidine, niclosamide, nitroscanate,paromomycin and paromomycin II.

In certain embodiments, the anthelmintic agent in the compositions ofthe invention can be a biologically active peptide or protein including,but not limited to, cyclic depsipeptides, which act at the neuromuscularjunction by stimulating presynaptic receptors belonging to the secretinreceptor family resulting in the paralysis and death of parasites. Inone particular embodiment of the cyclic depsipeptide, the depsipeptideis emodepside (see Willson et al., Parasitology, January 2003, 126(Pt1):79-86). In another embodiment, the cyclic depsipeptide is a compounddescribed in WO 2016/187534 or WO 2017/116702, both incorporated hereinby reference.

In another embodiment, anthelmintic compounds of the amino acetonitrileclass (AAD) of compounds such as monepantel (ZOLVIX) and the like may beincluded in the compositions of the invention. These compounds aredescribed, for example, in WO 2004/024704; Sager et al., VeterinaryParasitology, 2009, 159, 49-54; Kaminsky et al., Nature vol. 452, 13Mar. 2008, 176-181. The compositions of the invention may also includearyloazol-2-yl cyanoethylamino compounds such as those described in US2008/0312272 to Soll et al. and those described in U.S. patentapplication Ser. No. 12/618,308, and thioamide derivatives of thesecompounds, as described in U.S. patent application Ser. No. 12/582,486,filed Oct. 20, 2009, all of which are incorporated herein by reference.

The compositions of the invention may also be combined withparaherquamide compounds and derivatives of these compounds, includingderquantel (see Ostlind et al., Research in Veterinary Science, 1990,48, 260-61; and Ostlind et al., Medical and Veterinary Entomology, 1997,11, 407-408). The paraherquamide family of compounds are known class ofcompounds that include a spirodioxepino indole core with activityagainst certain parasites (see Tet. Lett. 1981, 22, 135; 1 Antibiotics1990, 43, 1380, and J. Antibiotics 1991, 44, 492). In addition, thestructurally related marcfortine family of compounds, such asmarcfortines A-C, are also known and may be combined with theformulations of the invention (see J. Chem. Soc.—Chem. Comm. 1980, 601and Tet. Lett. 1981, 22, 1977). Further references to the paraherquamidederivatives can be found, for example, in WO 91/09961, WO 92/22555, WO97/03988, WO 01/076370, WO 09/004432, U.S. Pat. Nos. 5,703,078 and5,750,695, all of which are hereby incorporated by reference in theirentirety.

In one embodiment, the invention provides a composition comprising atleast one avermectin or milbemycin active agent in combination with atleast one of a benzimidazole anthelmintic, an imidazothiazoleanthelmintic, a tetrahydropyrimidine anthelmintic, levamisole, pyrantelor praziquantel, in combination with a pharmaceutically acceptablecarrier or diluent, and optionally an antioxidant and/or a penetrationenhancer.

In another embodiment, the invention provides a composition comprisingat least one of abamectin, dimadectin, doramectin, emamectin,eprinomectin, ivermectin, latidectin, lepimectin, selamectin,milbemectin, milbemycin D, milbemycin oxime, moxidectin or nemadectin;and at least one of a benzimidazole anthelmintic, imidazothiazoleanthelmintic, tetrahydropyrimidine anthelmintic, levamisole, pyrantel orpraziquantel, together with a pharmaceutically acceptable carrier ordiluent, and optionally an antioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition (e.g.,spot-on, pour-on) consisting essentially of at least one of abamectin,dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin,lepimectin, selamectin, milbemectin, milbemycin D, milbemycin oxime,moxidectin or nemadectin and at least one of a benzimidazoleanthelmintic, imidazothiazole anthelmintic, tetrahydropyrimidineanthelmintic, levamisole, pyrantel or praziquantel, in combination witha pharmaceutically acceptable carrier or diluent, and optionally anantioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition consistingessentially of eprinomectin and praziquantel; in combination with apharmaceutically acceptable carrier or diluent, and optionally anantioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition consistingof eprinomectin and praziquantel; in combination with a pharmaceuticallyacceptable carrier or diluent, and optionally an antioxidant and/or apenetration enhancer

In another embodiment, the invention provides a topical veterinarycomposition having an extended shelf-life consisting essentially ofabout 0.01% (w/v) to about 10% (w/v) eprinomectin; about 1.0% (w/v) toabout 30.0% (w/v) praziquantel; about 0.01% (w/v) to about 2.0% (w/v)BHT; about 20% (w/s) to about 35.0% (w/v) glycerol formal; and about50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, wherein thecomposition has a shelf-life of at least 6 months, at least 12 months,at least 18 months, at least 24 months, at least 36 months, or at least48 months. In yet another embodiment, composition consists essentiallyof about 0.1% (w/v) to about 5.0% (w/v) eprinomectin; about 5.0% (w/v)to about 15.0% (w/v) praziquantel; about 0.01% (w/v) to about 1.0% (w/v)BHT; about 25% (w/s) to about 35.0% (w/v) glycerol formal; and about55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide. In yet anotherembodiment, the composition consists essentially of about 0.1% (w/v) toabout 1.0% (w/v) eprinomectin; about 8.0% (w/v) to about 12.0% (w/v)praziquantel; about 0.01% (w/v) to about 1.0% (w/v) BHT; about 25% (w/s)to about 35.0% (w/v) glycerol formal; and about 55.0% (w/v) to about65.0% (w/v) dimethyl isosorbide.

In yet another embodiment, the invention provides a topical veterinarycomposition having an extended shelf-life consisting essentially ofabout 0.01% (w/v) to about 10% (w/v) eprinomectin; about 1.0% (w/v) toabout 30.0% (w/v) praziquantel; about 0.01% (w/v) to about 2.0% (w/v)BHT; about 20% (w/s) to about 35.0% (w/v) unstabilized glycerol formal;and about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, whereinthe composition has a shelf-life of at least 6 months, at least 12months, at least 18 months, at least 24 months, at least 36 months, orat least 48 months. In yet another embodiment, composition consistsessentially of about 0.1% (w/v) to about 5.0% (w/v) eprinomectin; about5.0% (w/v) to about 15.0% (w/v) praziquantel; about 0.01% (w/v) to about1.0% (w/v) BHT; about 25% (w/s) to about 35.0% (w/v) unstabilizedglycerol formal; and about 55.0% (w/v) to about 65.0% (w/v) dimethylisosorbide. In yet another embodiment, the composition consistsessentially of about 0.1% (w/v) to about 1.0% (w/v) eprinomectin; about8.0% (w/v) to about 12.0% (w/v) praziquantel; about 0.01% (w/v) to about1.0% (w/v) BHT; about 25% (w/s) to about 35.0% (w/v) unstabilizedglycerol formal; and about 55.0% (w/v) to about 65.0% (w/v) dimethylisosorbide. In one embodiment, the glycerol formal is unstabilized bythe absence of stabilizers, e.g., EDTA.

In another embodiment, the invention provides a topical veterinarycomposition having an extended shelf-life for treating or preventing aparasitic infection or infestation in an animal, the compositionconsisting essentially of about 0.40% (w/v) eprinomectin; about 8.30%(w/v) praziquantel; about 0.10% (w/v) BHT; about 30.38% (w/v) glycerolformal; and QS dimethyl isosorbide. In one embodiment, the glycerolformal is unstabilized by the absence of stabilizers, e.g., EDTA or2,6-di-tert-butyl-4-methyl phenol.

In another embodiment, the invention provides a topical veterinarycomposition having an extended shelf-life for treating or preventing aparasitic infection or infestation in an animal, the compositionconsisting of about 0.40% (w/v) eprinomectin; about 8.30% (w/v)praziquantel; about 0.10% (w/v) BHT; about 30.38% (w/v) glycerol formal;and QS dimethyl isosorbide. In one embodiment, the glycerol formal isunstabilized by the absence of stabilizers, e.g., EDTA or2,6-di-tert-butyl-4-methyl phenol.

The compositions of the invention, which include two different activeagents in a carrier system that is compatible with each active agent,have been surprisingly discovered to be stable, to have an extendedshelf-life, and to be effective against a broad spectrum ofectoparasites and/or endoparasites. It will be well apparent to one ofskill in the art that combination of two active agents in a singlecomposition without affecting the stability of the active agents duringstorage or the efficacy of each active upon administration is extremelydifficult and unpredictable. The two classes of active agents includedin the inventive compositions have substantially different structuresand consequently have different solubility and stability requirements.This presents a significant problem when including the multiple activeagents in a single formulation, particularly in formulations thatrequire the two active agents to be in solution, such as in spot-on orpour-on formulations. The solubility, log P, molecular weight and otherphysical characteristics of each active agent in the carrier systemaffects the ability to deliver the drug into the coat of the animal orto permeate the skin as required. The identification of a suitablecarrier system that will solubilize each active agent in a stablesolution while being able to deliver the active agents to the targetedlocation on the animal at the required concentration is a very difficulttask and is not predictable or obvious.

Furthermore, the identification of a suitable carrier system to producea stable, extended shelf-life composition comprising two differentclasses of active agents is challenging and unobvious.

It is well known in the art that it is very difficult to formulatemacrocyclic lactone active agents together with certain other activesdue to different carrier requirements and the susceptibility ofmacrocyclic lactones to degrade in certain solvents. Avermectins andmilbemycins are poorly soluble in water and not compatible with acidicconditions, while some anthelmintic agents such as levamisole are morewater soluble and require acidic pH for optimum stability (see US2006/0128641 A1). For example, WO 00/74489 describes liquid compositionscomprising a macrocyclic lactone and another anthelmintic (levamisole)where the composition contains separate phases which contain thedifferent active agents in order to meet the different solubility andstability requirements of each active. U.S. Pat. No. 6,489,303 to Jancyset al. describes that mixtures of a macrocyclic lactone and anotherinsoluble anthelmintic agent resulted in an increased rate ofdegradation of the macrocyclic lactone active agent, requiring theaddition of excess antioxidant to stabilize the mixture. Therefore, thecombination of two active agents, including a macrocyclic lactone, in asingle liquid composition that is both stable for an extended period oftime and efficacious against a broad spectrum of ectoparasites andendoparasites represents a significant achievement in the field ofveterinary medicine that is not predictable or obvious.

The compositions of the present invention combine active agents that areefficacious against internal and/or external parasites. The compositionsof the invention, which in some embodiments are in the form of topicalsolutions in a homogeneous carrier, are unique in that they achieveexcellent long-lasting efficacy against external parasites such as fleasand ticks and/or effectively controlling internal parasites such asDirofilaria immitis (heartworm), roundworms and other parasitic worms.The compositions of the invention surprisingly achieve the requireddistribution of an effective amount each different active to the site ofthe animal required to achieve the superb efficacy against harmfulinternal and/or external parasites. In particular, the superb efficacyachieved against Dirofilaria immitis (heartworm), roundworms includingT. cati, tapeworms including D. caninum, and hookworms including A.tubaeforme is noteworthy and unique.

It is well know that macrocyclic lactone actives and anthelmintic activeagents are required to be absorbed into the blood stream to beefficacious against internal parasites. As such, some formulationsdirected to the treatment and control of endoparasites may containstrong solvents and/or penetration enhancing agents that can disrupt thebarrier function of the stratum corneum to allow passage of the activesinto the blood stream. Penetration enhancers include compounds with apolar head group and long alkyl chains such as non-ionic surfactants,oleic acid, propylene glycol, decyl methyl sulphoxide and Azone, amongothers.

In an embodiment of the inventive compositions, the composition will bein the form of a liquid solution or suspension. The pharmaceuticallyacceptable carrier may be any suitable carrier or diluent commonly usedin the formulation art including aqueous or organic solvents or mixturesof solvents. These organic solvents may be found, for example, inRemington Pharmaceutical Sciences, 16^(th) Edition (1986). Organicsolvents that can be used in the invention include those describedabove, and include but are not limited to: acetyltributyl citrate, oleicacid, fatty acid esters such as the dimethyl ester, diisobutyl adipate,diisopropyl adipate (also known as CERAPHYL 230), ketones includingacetone, methylisobutyl ketone (MIK) and methyl ethyl ketone and thelike, acetonitrile, benzyl alcohol, methanol, ethyl alcohol,isopropanol, butanol, aromatic ethers such as anisole, butyl diglycol,amides including dimethylacetamide and dimethylformamide, dimethylsulfoxide, ethylene glycol, propylene glycol, glycol ethers includingpropylene glycol monomethyl ether, propylene glycol monoethyl ether,dipropylene glycol n-butyl ether, ethylene glycol monoethyl ether,ethylene glycol monomethyl ether, diethylene glycol monoethyl ether,glycol carbonates, monomethylacetamide, dipropylene glycol monomethylether, liquid polyoxyethylene glycols (PEG) of different averagemolecular weight ranges, 2-pyrrolidone including N-methylpyrrolidone,glycerol formal, dimethyl isosorbide, triacetin, C₁-C₁₀ esters ofcarboxylic acids such as butyl or octyl acetate, benzyl acetate, arylesters including benzyl benzoate, ethyl benzoate and the like, propylenecarbonate, butylene carbonate, and diethyl phthalate, or a mixture of atleast two of these solvents.

These solvents can be supplemented by various excipients according tothe nature of the desired phases, such as C₈-C₁₀ caprylic/caprictriglyceride (ESTASAN or MIGLYOL 812), oleic acid or propylene glycol.

In one embodiment of the invention, the pharmaceutically acceptablecarrier of the formulation comprises C₁-C₁₀ alcohols or esters thereof(including acetates, such as ethyl acetate and the like), C₁₀-C₁₈saturated fatty acids or esters thereof, C₁₀-C₁₈ monounsaturated fattyacids or esters thereof, monoesters or diesters of aliphatic diacids, ormixtures thereof.

In some embodiments, the carrier or diluent is a derivative of glycerolincluding, but not limited to, glycerol monoesters (e.g.monoglycerides), glycerol diesters (e.g. diglycerides), glyceroltriesters (e.g. triglycerides such as triacetin), or glycerol formal, ormixtures thereof. Glycerol formal is a mixture of 5-hydroxy-1,3-dioxaneand 4-hydroxymethyl-1,3-dioxolane (approximately 60:40), which arecyclic ether compounds derived from glycerol and having 2 oxygen atomsin the ring structure and substituted by alcohol group. Glycerol Formalis a low odor and low toxic solvent for a wide variety of applicationsin pharmaceutical and cosmetics industry including anti-parasiteveterinary formulations.

In another embodiment of the invention, the organic solvents maycomprise diisopropyl adipate, dipropylene glycol monomethyl ether,propylene glycol monomethyl ether, 2-pyrrolidone includingN-methylpyrrolidone, diethylene glycol monoethyl ether, triacetin, butylacetate, octyl acetate, propylene carbonate, oleic acid, or a mixture ofat least two of these solvents.

In one embodiment, the solvents include C₁-C₁₀ esters of carboxylicacids such as butyl or octyl acetate.

In some embodiments of the invention, the carrier comprises dimethylisosorbide. Dimethyl Isosorbide (DMI) is a high purity solvent andcarrier which offers a safe, effective delivery enhancement mechanismfor active ingredients in personal care products and pharmaceuticalformulations. In addition dimethyl isosorbide is sometimes used as anepidermal penetration enhancer to provide enhanced penetration of activeagents to the epidermis. It may also provide delivery of active agentsinto the skin while avoiding crystallization of the active agent, whichwill severely limit the effectiveness of the formulation. DimethylIsosorbide is soluble in a variety of ingredients including water,cottonseed oil, isopropanol, isopropyl myristate, propylene glycol,polysorbate 20, and polysorbate 80. It is insoluble in hydrogenatedcastor oil, lanolin, mineral oils or silicone oil (dimethicone).

In other embodiments, the carrier or diluent can be dimethyl sulfoxide(DMSO), glycol derivatives such as, for example, propylene glycol,glycol ethers, polyethylene glycols or glycerol. As vehicle or diluent,mention may also be made of plant oils such as, but not limited tosoybean oil, groundnut oil, castor oil, corn oil, cotton oil, olive oil,grape seed oil, sunflower oil, etc.; mineral oils such as, but notlimited to, petrolatum, paraffin, silicone, etc.; aliphatic or cyclichydrocarbons or alternatively, for example, medium-chain (such as C₈ toC₁₂) triglycerides, or mixtures thereof.

In an embodiment, the carrier or diluent is a mixture of glycerol formaland dimethyl isosorbide. In another embodiment, the glycerol formal isunstabilized by the absence of stabilizers. In yet another embodiment,the glycerol formal is unstabilized by the absence of EDTA or6-di-tert-butyl-4-methyl phenol.

Glycerol formal is commonly available commercially as stabilizedglycerol formal by the inclusion of a small amount of stabilizers suchas EDTA or 6-di-tert-butyl-4-methyl phenol. In one embodiment of theinvention, Applicant surprisingly found that using unstabilized glycerolformal in the formulation, particularly glycerol formal without EDTA or6-di-tert-butyl-4-methyl phenol, results in a composition having anextended shelf-life, for example, by at least 6 months, at least 12months, at least 18 months, at least 24 months, at least 36 months, orat least 48 months.

Typically the amount of glycerol formal in the composition is about 20%(w/s) to about 35.0% (w/v), preferably about 25% (w/s) to about 35.0%(w/v) or about 25% (w/s) to about 35.0% (w/v). In an embodiment,glycerol formal is present in the composition at about 30.38% (w/v).

The amount of dimethyl isosorbide in the compositions of the presentinvention is typically about 50.0% (w/v) to about 75.0% (w/v),preferably about 55.0% (w/v) to about 65.0% (w/v) or about 55.0% (w/v)to about 65.0% (w/v). In an embodiment, dimethyl isosorbide is presentin the composition at about 62.82% (w/v) or QS.

The compositions of the invention can be in a variety of forms suitablefor different forms of administration including, but are not limited to,oral formulations, injectable formulations, and topical, dermal orsubdermal formulations.

In some embodiments the compositions of the invention may be in a formsuitable for oral use, for example, as baits (see, e.g., U.S. Pat. No.4,564,631, incorporated herein by reference), dietary supplements,troches, lozenges, chewables, tablets, hard or soft capsules, emulsions,aqueous or oily suspensions, aqueous or oily solutions, oral drenchformulations, dispersible powders or granules, syrups or elixirs,enteric formulations or pastes. Compositions intended for oral use maybe prepared according to any method known in the art for the manufactureof pharmaceutical compositions and such compositions may contain one ormore agents selected from the group consisting of sweetening agents,bittering agents, flavoring agents, coloring agents and preservingagents in order to provide pharmaceutically elegant and palatablepreparations.

Tablets may contain the active ingredient in admixture with non-toxic,pharmaceutically acceptable excipients which are suitable for themanufacture of tablets. These excipients may be, for example, inertdiluents, such as calcium carbonate, sodium carbonate, lactose, calciumphosphate or sodium phosphate; granulating and disintegrating agents,for example, corn starch, or alginic acid; binding agents, for examplestarch, gelatin or acacia, and lubricating agents, for example,magnesium stearate, stearic acid or talc, the tablets may be uncoated orthey may be coated by known techniques to delay disintegration andabsorption in the gastrointestinal tract and thereby provide a sustainedaction over a longer period. For example, a time delay material such asglyceryl monostearate or glyceryl distearate may be employed. They mayalso be coated by the technique described in U.S. Pat. Nos. 4,256,108;4,166,452; and 4,265,874, which are incorporated herein by reference intheir entirety, to form osmotic therapeutic tablets for controlledrelease.

Formulations for oral use may be hard gelatin capsules, wherein theactive ingredient is mixed with an inert solid diluent, for example,calcium carbonate, calcium phosphate or kaolin. Capsules may also besoft gelatin capsules, wherein the active ingredient is mixed with wateror miscible solvents such as propylene glycol, PEGs and ethanol, or anoil medium, for example peanut oil, liquid paraffin, or olive oil.

The compositions of the invention may also be in the form ofoil-in-water or water-in-oil emulsions. The oily phase may be avegetable oil, for example, olive oil or arachis oil, or a mineral oil,for example, liquid paraffin or mixtures of these. Suitable emulsifyingagents may be naturally-occurring phosphatides, for example, soy bean,lecithin, and esters or partial esters derived from fatty acids andhexitol anhydrides, for example, sorbitan monoleate, and condensationproducts of the said partial esters with ethylene oxide, for example,polyoxyethylene sorbitan monooleate. The emulsions may also containsweetening agents, bittering agents, flavoring agents, and/orpreservatives.

In one embodiment of the formulation, the composition of the inventionis in the form of a microemulsion. Microemulsions are well suited as theliquid carrier vehicle. Microemulsions are quaternary systems comprisingan aqueous phase, an oily phase, a surfactant and a cosurfactant. Theyare translucent and isotropic liquids. Microemulsions are composed ofstable dispersions of microdroplets of the aqueous phase in the oilyphase or conversely of microdroplets of the oily phase in the aqueousphase. The size of these microdroplets is less than 200 nm (1000 to100,000 nm for emulsions). The interfacial film is composed of analternation of surface-active (SA) and co-surface-active (Co-SA)molecules which, by lowering the interfacial tension, allows themicroemulsion to be formed spontaneously.

In one embodiment of the oily phase, the oily phase can be formed frommineral or vegetable oils, from unsaturated polyglycosylated glyceridesor from triglycerides, or alternatively from mixtures of such compounds.In one embodiment of the oily phase, the oily phase comprises oftriglycerides. In another embodiment of the oily phase, thetriglycerides are medium-chain triglycerides, for example C₈-C₁₀caprylic/capric triglyceride. Another embodiment of the oily phase willrepresent a % v/v range selected from the group consisting of about 2 toabout 15%; about 7 to about 10%; and about 8 to about 9% v/v of themicroemulsion.

The aqueous phase includes, for example water or glycol derivatives,such as propylene glycol, glycol ethers, polyethylene glycols orglycerol. In one embodiment of the glycol derivatives, the glycol isselected from the group consisting of propylene glycol, diethyleneglycol monoethyl ether, dipropylene glycol monoethyl ether and mixturesthereof. Generally, the aqueous phase will represent a proportion fromabout 1 to about 4% v/v in the microemulsion.

Surfactants for the microemulsion include diethylene glycol monoethylether, dipropyelene glycol monomethyl ether, polyglycolyzed C₈-C₁₀glycerides or polyglyceryl-6 dioleate. In addition to these surfactants,the cosurfactants include short-chain alcohols, such as ethanol andpropanol.

Some compounds are common to the three components discussed above, i.e.,aqueous phase, surfactant and cosurfactant. However, it is well withinthe skill level of the practitioner to use different compounds for eachcomponent of the same formulation.

Oily suspensions may be formulated by suspending the active ingredientin a vegetable oil, for example, arachis oil, olive oil, sesame oil orcoconut oil, or in mineral oil such as liquid paraffin. The oilysuspensions may contain a thickening agent, for example, beeswax, hardparaffin or cetyl alcohol. Sweetening agents such as sucrose, saccharinor aspartame, bittering agents, and flavoring agents may be added toprovide a palatable oral preparation. These compositions may bepreserved by the addition of an anti-oxidant such as ascorbic acid orother known preservatives.

Aqueous suspensions may contain the active agents in admixture withexcipients suitable for the manufacture of aqueous suspensions. Suchexcipients are suspending agents, for example, sodiumcarboxymethylcellulose, methylcellulose, hydroxy-propylmethylcellulose,sodium alginate, polvinylpyrrolidone, gum tragacanth and gum acacia;dispersing or wetting agents may be a naturally-occurring phosphatide,for example lecithin, or condensation products of an alkylene oxide withfatty acids, for example polyoxyethylene stearate, or condensationproducts of ethylene oxide with long chain aliphatic alcohols, forexample, heptadecaethyleneoxycetanol, or condensation products ofethylene oxide with partial esters derived from fatty acids and ahexitol such as polyoxyethylene sorbitol monooleate, or condensationproducts of ethylene oxide, with partial esters derived from fatty acidsand hexitol anhydrides, for example polyethylene sorbitan monooleate.The aqueous suspensions may also contain one or more preservatives, forexample ethyl, or n-propyl, p-hydroxybenzoate, one or more coloringagents, one or more flavoring agents, and one or more sweetening agentsand/or bittering agents, such as those set forth above.

Syrups and elixirs may be formulated with sweetening agents, forexample, glycerol, propylene glycol, sorbitol or sucrose. Suchformulations may also contain a demulcent, a preservative, flavoringagent(s) and/or coloring agent(s).

In another embodiment of the invention, the composition can be in pasteform. Examples of embodiments in a paste form include but are notlimited to those described in U.S. Pat. Nos. 6,787,342 and 7,001,889,both of which are incorporated herein by reference. In addition to theactive agent of the invention, the paste can also contain fumed silica;a viscosity modifier; a carrier; optionally, an absorbent; andoptionally, a colorant, stabilizer, surfactant, or preservative.

In one embodiment, the process for preparing a paste formulationcomprises the steps of:

(a) dissolving or dispersing the active agent into the carrier bymixing;

(b) adding the fumed silica to the carrier containing the dissolvedactive agent compound and mixing until the silica is dispersed in thecarrier;

(c) allowing the intermediate formed in (b) to settle for a timesufficient in order to allow the air entrapped during step (b) toescape; and

(d) adding the viscosity modifier to the intermediate with mixing toproduce a uniform paste.

The above steps are illustrative, but not limiting. For example, step(a) can be the last step.

In one embodiment of the formulation, the formulation is a pastecontaining the active agent compound, fumed silica, a viscositymodifier, an absorbent, a colorant; and a hydrophilic carrier which is atriacetin, a monoglyceride, a diglyceride, or a triglyceride. The pastemay also include a viscosity modifier including, but is not limited to,PEG 200, PEG 300, PEG 400, PEG 600, monoethanolamine, triethanolamine,glycerol, propylene glycol, polyoxyethylene (20) sorbitan mono-oleate(polysorbate 80 or Tween 80), or polyoxamers (e.g., Pluronic L 81); anabsorbent including, but not limited to, magnesium carbonate, calciumcarbonate, starch, or cellulose and its derivatives.

Colorants may be added to the inventive formulations. Colorantscontemplated by the present invention are those commonly known in theart. Specific colorants include, for example, dyes, FD&C Blue #1Aluminum Lake, caramel, colorant based upon iron oxide or a mixture ofany of the foregoing. Especially preferred are organic dyes and titaniumdioxide. Preferred ranges include from about 0.5% to about 25%.

In some embodiments of the invention, the compositions may be in theform of a sterile injectable solutions or aqueous or oleagenoussuspensions. These suspensions may be formulated according to the knownart using those suitable dispersing or wetting agents and suspendingagents which have been mentioned above. The sterile injectablepreparation may also be a sterile injectable solution or suspension in anon-toxic parenterally-acceptable diluent or solvent, for example, as asolution in 1,3-butane diol. Among the acceptable vehicles and solventsthat may be employed are water, Ringer's solution and isotonic sodiumchloride solution. Cosolvents such as ethanol, propylene glycol orpolyethylene glycols may also be used. Preservatives, such as phenol orbenzyl alcohol, may be used.

In addition, sterile, fixed oils are conventionally employed as asolvent or suspending medium. For this purpose any bland fixed oil maybe employed including synthetic mono- or diglycerides. In addition,fatty acids such as oleic acid find use in the preparation ofinjectables.

In one embodiment of the invention, compositions suitable for topicaladministration to an animal are provided. Topical, dermal and subdermalformulations can include emulsions, creams, ointments, gels, pastes,powders, shampoos, pour-on formulations, ready-to-use formulations,spot-on solutions and suspensions.

In an embodiment, the compositions of the invention are in the form of aspot-on formulation that is applied to a localized area on an animal,rather than the entire coat of the animal or a large portion of theanimal's coat. In one embodiment of a localized region, the location isbetween the shoulders. The spot-on formulation according to the presentinvention provide long-lasting and broad-spectrum efficacy againstectoparasites and/or endoparasites when the solution is applied to themammal or bird. The spot-on formulations provide for topicaladministration of a concentrated solution, suspension, microemulsion oremulsion for intermittent application to a spot on the animal, generallybetween the two shoulders (solution of spot-on type).

Spot-on formulations are well known techniques for topically deliveringan antiparasitic agent to a limited area of the host. For example, U.S.Pat. Nos. 5,045,536 6,426,333; 6,482,425; 6,962,713; and 6,998,131, allincorporated herein by reference, describe spot-on formulations. WO01/957715, also incorporated herein by reference, describes a method forcontrolling ectoparasites in small rodents as well as interrupting orpreventing the diseases caused by arthropods in small rodents, whichcomprise applying topical formulations, such as spot-on compositions, tothe skin, or hair of the rodents.

For spot-on formulations, the pharmaceutically acceptable carrier may bea liquid carrier vehicle as described herein, and other carriersdescribed in the art, for example in U.S. Pat. No. 6,426,333, which isincorporated herein by reference. In some embodiments, the liquidcarrier vehicle can optionally contain a crystallization inhibitor suchas the crystallization inhibitors to inhibit the formation of crystalsor precipitate of the active components.

The veterinarily acceptable carrier will generally comprise a diluent orvehicle in which the active agents are soluble. It will be apparent tothose of skill in the art that the carrier or diluent of the topicalcompositions must be able to deliver the active agents to the targetedlocation without the active agents precipitating from solution orforming crystals. In some embodiments, the carrier or diluent of thecompositions will be suitable to avoid precipitation or crystallizationof the active agents. In other embodiments, the compositions may includea crystallization inhibitor in addition to the carrier or diluent.

In one embodiment of the invention, the carrier for spot-on compositionsmay comprise diisopropyl adipate, dipropylene glycol monomethyl ether,propylene glycol monomethyl ether, 2-pyrrolidone, N-methylpyrrolidone,diethylene glycol monoethyl ether, triacetin, butyl acetate, octylacetate, propylene carbonate, oleic acid, or a mixture of at least twoof these solvents.

In another embodiment of the invention, the pharmaceutically acceptablecarrier of the formulation comprises C₁-C₁₀ alcohols or esters thereof(including acetates, such as ethyl acetate and the like), C₁₀-C₁₈saturated fatty acids or esters thereof, C₁₀-C₁₈ monounsaturated fattyacids or esters thereof, monoesters or diesters of aliphatic diacids, ormixtures thereof.

In yet another embodiment, preferred solvents include C₁-C₁₀ esters ofcarboxylic acids such as butyl or octyl acetate.

In one embodiment, the compositions of the invention that are suitablefor topical administration will comprise glycerol derived carriersincluding glycerol monoesters (e.g. monoglycerides), glycerol diesters(e.g. diglycerides), glycerol triesters (e.g. triglycerides such astriacetin), glycerol formal, or mixtures thereof.

In another embodiment, the compositions of the invention for topicaladministration will comprise an alcohol including ethanol orisopropanol; propylene glycol, dimethyl isosorbide (DMI), 2-pyrrolidone,N-methylpyrrolidone, dimethylsulfoxide, glycerol formal, glycol ethersincluding diethylene glycol monoethyl ether, diethylene glycolmonomethyl ether and the like, or mixtures thereof.

In yet another embodiment, the topical compositions of the inventionwill comprise glycerol formal, dimethyl isosorbide, N-methylpyrrolidone,diethylene glycol monoethyl ether, or mixtures thereof. In still anotherembodiment, the topical compositions will comprise glycerol formal,dimethyl isosorbide, or a mixture thereof.

Spot-on formulations, described for example in U.S. Pat. No. 7,262,214(incorporated herein by reference), may be prepared by dissolving theactive ingredients into the pharmaceutically or veterinary acceptablevehicle. Alternatively, the spot-on formulation can be prepared byencapsulation of the active ingredients to leave a residue of thetherapeutic agent on the surface of the animal. These formulations willvary with regard to the weight of the therapeutic agent in thecombination depending on the species of host animal to be treated, theseverity and type of infection and the body weight of the host.

Pour-on formulations are described, for example, in U.S. Pat. No.6,010,710, which is incorporated herein by reference. Some pour-onformulations are advantageously oily, and generally comprise a diluentor vehicle and also a solvent (e.g. an organic solvent) for the activeingredient if the latter is not soluble in the diluent. Other pour-onformulations may be in hydrophilic carriers. Pour-on formulation may beadministered to livestock animals such as cattle and sheep. Typically,pour-on formulations are administered to the animal as a stripe to anexternal surface of the animal, e.g. a stripe from head to tail of theanimal. In one embodiment, the process comprises applying the solutionto livestock animals before they arrive in the Feed Lot, it beingpossible for this application to be the final one before the animals areslaughtered.

The compositions of the invention can also be formed in a collar such asthose described in U.S. Pat. No. 5,885,607, which is incorporated hereinby reference. Within the scope of the invention, matrices usually usedto make collars may be used. In one embodiment of the collars which maybe mentioned are matrices based on PVC (polyvinyl chloride), asdescribed in U.S. Pat. Nos. 3,318,769; 3,852,416; 4,150,109 and5,437,869, (all incorporated by reference) and other vinyl polymers.

The plasticizers may be chosen in particular from adipates, phthalates,phosphates and citrates. In another embodiment of the collar, one ormore plasticizers are also added to the PVC, these plasticizers beingchosen in particular from the following compounds: diethyl phthalate,dioctyl sebacate, dioctyl adipate, diisodecyl phthalate, acetyl tributylcitrate, diethyl hexyl phthalate, di-n-butyl phthalate, benzyl butylphthalate, acetyl tributyl citrate, tricresyl phosphate, and2-ethylhexyl diphenyl phosphate.

In another embodiment of the collar, a PVC matrix will be used in thepresence of a primary remanent plasticizer and a secondary plasticizer,in particular according to EP 0 539 295 and EP 0 537 998.

Among the secondary plasticizers, mention may be made of the followingproducts: acetyl triethyl citrate, triethyl citrate, triacetin,diethylene glycol monoethyl ether, triphenyl phosphate. A commonstabilizer may also be added thereto.

For the purposes of the present invention, the term external deviceshould be understood to refer to any device which can be attachedexternally to the animal in order to provide the same function as acollar.

Typically the formulations of the invention will comprise about 0.01 toabout 10% (w/v) of the macrocyclic lactone active agent(s). Moretypically, the formulations will contain about 0.01 to about 5% or about0.01% to about 2% (w/v) of the macrocyclic lactone active agent(s). Insome embodiments, the formulations will contain about 0.1 to about 5% orabout 0.1 to about 1% (w/v) of the macrocyclic lactone active agent(s).In other embodiments, the formulations will contain about 0.4% (w/v) ofthe macrocyclic lactone.

The amount of the anthelmintic active agent(s) in the formulations ofthe invention will typically be from about 1 to about 30% (w/v). Moretypically, the formulations will contain from about 1 to about 20%(w/v), about 5 to about 15% (w/v) or about 8 to about 12% (w/v). In someembodiments, the formulations will contain about 8.3% (w/v) of theanthelmintic active agent.

In one embodiment, the formulations of the invention will comprise orconsist essentially of about 0.01 to about 5% of at least onemacrocyclic lactone(s) and about 5 to about 15% (w/v) of at least oneanthelmintic active agent(s).

In another embodiment, the compositions of the invention will compriseor consist essentially of about 0.01 to about 5% of eprinomectin andabout 5 to about 15% (w/v) of praziquantel, in combination with apharmaceutically acceptable carrier or diluent, and optionally anantioxidant and/or a penetrating enhancer.

In yet another embodiment, the composition will comprise or consistessentially of about 0.4% (w/v) of eprinomectin and about 8.3% (w/v) ofpraziquantel.

In still another embodiment, the compositions of the invention willcomprise or consist essentially of about 0.01 to about 2% (w/v)eprinomectin and about 5 to about 15% (w/v) praziquantel, in combinationwith about 80 to 95% (w/v) pharmaceutically acceptable carrier ordiluent.

In an embodiment, the compositions of the invention comprise or consistessentially of about 0.01 to 2% (w/v) eprinomectin and about 8 to about12% (w/v) praziquantel, in combination with about 80 to 95% (w/v)pharmaceutically acceptable carrier or diluent. In another embodiment,the pharmaceutically acceptable carrier is a mixture of about 20.0 toabout 35.0% (w/v) glycerol formal and about 50.0 to about 75.0% (w/v)dimethyl isosorbide, preferably about 25.0 to about 35.0% (w/v) glycerolformal and about 55.0 to about 65.0% (w/v) dimethyl isosorbide. In yetanother embodiment, the glycerol formal is unstabilized by the absenceof stabilizers, e.g., EDTA or 6-di-tert-butyl-4-methyl phenol.

In one embodiment, the compositions of the invention will comprise orconsist essentially of about 0.4% (w/v) of eprinomectin and about 8.3%(w/v) of praziquantel, in combination with a pharmaceutically acceptablecarrier or diluent. In another embodiment, the pharmaceuticallyacceptable carrier or diluent is glycerol formal, dimethyl isosorbide,or a mixture thereof. In yet another embodiment, the glycerol formal isunstabilized by the absence of stabilizers. In yet another embodiment,the glycerol formal is unstabilized by the absence of EDTA or6-di-tert-butyl-4-methyl phenol.

In an embodiment, the compositions of the invention will comprise orconsist essentially of about 0.4% (w/v) of eprinomectin and about 8.3%(w/v) of praziquantel, in combination with a pharmaceutically acceptablecarrier or diluent, and optionally an antioxidant and/or a penetrationenhancer. In another embodiment, the pharmaceutically acceptable carrieror diluent is glycerol formal, dimethyl isosorbide, or a mixturethereof, and the antioxidant is BHT or BHA. In yet another embodiment,the glycerol formal is unstabilized by the absence of stabilizers. Inyet another embodiment, the glycerol formal is unstabilized by theabsence of EDTA or 6-di-tert-butyl-4-methyl phenol. In one embodiment,the penetration enhancer is propylene glycol.

In one embodiment, the compositions of the invention will comprise orconsist essentially of about 0.4% (w/v) of eprinomectin and about 8.3%(w/v) of praziquantel, in combination with about 0.1% (w/v) of theantioxidant, and a pharmaceutically acceptable carrier or diluent. Inanother embodiment, the pharmaceutically acceptable carrier or diluentis glycerol formal, dimethyl isosorbide, or a mixture thereof, and theantioxidant is BHT or BHA. In yet another embodiment, the glycerolformal is unstabilized by the absence of stabilizers. In yet anotherembodiment, the glycerol formal is unstabilized by the absence of EDTAor 6-di-tert-butyl-4-methyl phenol. In yet another embodiment, theamount of glycerol formal in the compositions is about 30.38% (w/v) andQS of dimethyl isosorbide.

In an embodiment, the compositions of the invention will consistessentially of about 0.4% (w/v) eprinomectin, 8.3% (w/v) praziquantel,0.1% (w/v) BHT, 30.38% (w/v) unstabilized glycerol formal, and QS or60.82% (w/v) dimethyl isosorbide.

In one embodiment, the compositions of the invention may consist ofeprinomectin, praziquantel, an antioxidant, and a pharmaceuticallyacceptable carrier or diluent. In another embodiment, the amount ofeprinomectin in the compositions is about 0.4% (w/v) and the amount ofpraziquantel is about 8.3% (w/v). In yet another embodiment, theantioxidant is BHT or BHA and in an amount of about 0.1% (w/v). In yetanother embodiment, the pharmaceutically acceptable carrier or diluentis a mixture of 30.38% (w/v) unstabilized glycerol formal, and QS or60.82% (w/v) dimethyl isosorbide.

In some embodiments of the invention, an emollient and/or spreadingand/or film-forming agent may be added to the topical compositions ofthe invention. In some embodiments the emollient and/or spreading and/orfilm-forming agents include:

(a) polyvinylpyrrolidone, polyvinyl alcohols, copolymers of vinylacetate and vinylpyrrolidone, polyethylene glycols, benzyl alcohol,mannitol, glycerol, sorbitol, polyoxyethylenated sorbitan esters;lecithin, sodium carboxymethylcellulose, silicone oils,polydiorganosiloxane oils (such as polydimethylsiloxane (PDMS) oils),for example those containing silanol functionalities, or a 45V2 oil,

(b) anionic surfactants such as alkaline stearates, sodium, potassium orammonium stearates; calcium stearate, triethanolamine stearate; sodiumabietate; alkyl sulfates (e.g. sodium lauryl sulfate and sodium cetylsulfate); sodium dodecylbenzenesulphonate, sodiumdioctylsulphosuccinate; fatty acids (e.g. those derived from coconutoil),

(c) cationic surfactants such as water-soluble quaternary ammonium saltsof formula N⁺R′R″R′″R″″Y⁻, in which the R radicals are optionallyhydroxylated hydrocarbon radicals and Y⁻ is an anion of a strong acidsuch as the halide, sulfate and sulphonate anions;cetyltrimethylammonium bromide is among the cationic surfactants whichcan be used,

(d) amine salts of formula N⁺ R′R″R′″ in which the R radicals areoptionally hydroxylated hydrocarbon radicals; octadecylaminehydrochloride is among the cationic surfactants which can be used,

(e) nonionic surfactants such as sorbitan esters, which are optionallypolyoxyethylenated (e.g. polysorbate 80), polyoxyethylenated alkylethers; polyoxypropylated fatty alcohols such as polyoxypropylene-styrolether; polyethylene glycol stearate, polyoxyethylenated derivatives ofcastor oil, polyglycerol esters, polyoxyethylenated fatty alcohols,polyoxyethylenated fatty acids, copolymers of ethylene oxide andpropylene oxide,

(f) amphoteric surfactants such as the substituted lauryl compounds ofbetaine, and

(g) a mixture of at least two of these agents.

In one embodiment, the emollient is used in a proportion of from about0.1 to about 10%, or about 0.25 to about 5% (w/v).

The volume of the topical composition applied is not restricted as longas the amount of substance administered is shown to be safe andefficacious. Typically, the volume applied depends on the size andweight of the animal as well as the concentration of active, the extentof infestation by parasites and the type of administration. For spot-oncompositions, the volume applied is typically of the order of about 0.1to about 1 ml, or about 0.1 ml to about 5 ml, or about 0.1 ml to about10 ml. In other embodiments, the volume may be about 4 ml to about 7 ml.For larger animals, the volume may be higher including, but not limitedto, up to 10 ml, up to 20 ml or up to 30 ml, or higher. In oneembodiment of the volume, the volume is on the order of about 0.5 ml toabout 1 ml or about 0.5 ml to about 2 ml for cats, and on the order ofabout 0.3 to about 3 ml or 4 ml for dogs, depending on the weight of theanimal. In another embodiment, the volume of the spot-on composition foradministration to cats is about 0.3 ml. In another embodiment, thevolume is about 0.9 ml.

For the pour-on form of the composition, the volume applied can be ofthe order of about 0.3 to about 100 mL. In other embodiments, volumeapplied of the pour-on formulations may be about 1 ml to about 100 ml orabout 1 ml to about 50 ml. In still other embodiments, the volume may beabout 5 ml to about 50 ml or about 10 ml to about 100 ml.

Dosage forms may contain from about 0.5 mg to about 5 g of a combinationof active agents. In one embodiment of the dosage form, the dosage isfrom about 1 mg to about 500 mg of an active agent, typically about 25mg, about 50 mg, about 100 mg, about 200 mg, about 300 mg, about 400 mg,about 500 mg, about 600 mg, about 800 mg, or about 1000 mg.

Methods of Treatment

In another aspect of the invention, a method for preventing or treatinga parasite infestation/infection in an animal is provided, comprisingadministering a composition described herein, for example, a compositioncomprising an effective amount of at least one macrocyclic lactoneactive agent in combination with at least one anthelmintic active agent,together with a pharmaceutically acceptable carrier, and optionally anantioxidant and/or a penetration enhancer. The compositions orformulations of the invention have an extended shelf-life and along-lasting efficacy against endoparasites and/or ectoparasites (e.g.fleas and ticks) that harm animals.

In one embodiment of the invention, methods for the treatment orprevention of a parasitic infestation or infection in a domestic animalare provided, which comprise administering a composition comprising aneffective amount of at least one macrocyclic lactone active agent and atleast one anthelmintic active agent to the animal. Ectoparasites againstwhich the methods and compositions of the invention are effectiveinclude, but are not limited to, fleas, ticks, mites, mosquitoes, fliesand lice. The compositions and methods of the invention are alsoeffective against endoparasites including, but not limited to, cestodes,nematodes, such as filariae, Dirofilaria immitis (heartworm), hookwormsand roundworms of the digestive tract of animals and humans. In oneembodiment, the compositions of the invention are effective forpreventing the infection of an animal by Dirofilaria immitis (heartworm)by killing the immature stages of the parasite before they can mature toadult worms.

In one embodiment, the invention provides methods for the treatment andprevention of parasitic infections and infestations of animals (eitherwild or domesticated), including livestock and companion animals such ascats, dogs, horses, chickens, sheep, goats, pigs, turkeys and cattle,with the aim of ridding these hosts of parasites commonly encountered bysuch animals.

In an embodiment, the invention provides methods and compositions forthe treatment or prevention of parasitic infections and infestations incompanion animals including, but not limited to, cats and dogs. In aparticularly embodiment of the invention, the methods and compositionsdescribed are used to prevent or treat parasitic infections orinfestations in cats.

By “treating” or “treat” or “treatment” is intended the application oradministration of a composition of the invention to an animal that has aparasitic infestation for the eradication of the parasite or thereduction of the number of the parasites infesting the animal undergoingtreatment. In one embodiment, the term “treating” or “treat” isunderstood to reduce the number of parasites in or on the animal byabout at least 70% relative to an untreated control group. In otherembodiments, “treating” or “treat” means reducing the number ofparasites by at least about 80%, at least about 85% or at least about90%. In another embodiment, “treating” or “treat” means reducing thenumber of parasites by at least about 95% or by 100%. It is noted thatthe compositions of the invention may be used to prevent such aparasitic infestation.

It will be appreciated by those of skill in the art that the methods ofthe invention encompass administering the macrocyclic lactone activeagent(s) and the anthelmintic active agent(s) together in the samecarrier or diluent or separately where each active agent or mixtures ofthe active agents are present in their own carriers or diluents. Forexample when the active agents are administered topically, themacrocyclic lactone active agent(s) may be administered at the samelocation on the animal at the same time as the anthelmintic activeagent(s), or the macrocyclic lactone active agent(s) may be administeredat a different location on the animal than the anthelmintic activeagent(s). Each active agent may be administered simultaneously orsequentially in separate carriers, which may be the same or different.Furthermore, each of the active compound(s) may be administered by thesame mode of administration (e.g. topical, oral, parenteral, etc.), orthe different active agents may be administered by different modes ofadministration. In an embodiment, the macrocyclic lactone active agentis eprinomectin and the anthelmintic active agent is praziquantel.

In one embodiment of the invention, the method comprises administeringeach of the macrocyclic lactone(s) and the anthelmintic(s) separatelyand sequentially. In another embodiment, the macrocyclic lactone activeagent is eprinomectin and the anthelmintic active agent is praziquantel.

In another embodiment of the invention, the method comprisesadministering each of the macrocyclic lactone(s) and the anthelmintic(s)simultaneously. In yet another embodiment, the macrocyclic lactoneactive agent is eprinomectin and the anthelmintic active agent ispraziquantel.

In yet another embodiment of the invention, the method comprisesadministering each of the macrocyclic lactone(s) and the anthelmintic(s)simultaneously in the same carrier or diluent. In one embodiment, themacrocyclic lactone active agent is eprinomectin and the anthelminticactive agent is praziquantel.

In still another embodiment, the method comprises administeringmacrocyclic lactone active agent(s) and the anthelmintic active agent(s)separately in a separate carrier, which may be the same or different forthe two active agents. In one embodiment, the macrocyclic lactone activeagent is eprinomectin and the anthelmintic active agent is praziquantel.

In another aspect of the invention, a kit for the treatment orprevention of a parasitic infestation in an animal is provided, whichcomprises at least one macrocyclic lactone(s) and at least oneanthelmintic(s) together with a pharmaceutically acceptable carrier anda dispensing device for topical application of the composition. Thedispensing device may be a pipette, syringes, roll on, droppers,capsules, foil packages, vials, twist tip containers and other singledose and multi-dose containers, which includes an effective dose of eachactive agent in the pharmaceutically acceptable carrier or diluent. Inone embodiment, the macrocyclic lactone active agent is eprinomectin andthe anthelmintic active agent is praziquantel.

The compositions of the invention may be administered to the animal atdifferent intervals depending on the dose administered. In oneembodiment, the compositions of the invention may be administered to theanimal monthly. In other embodiments, the compositions may beadministered twice a month or even weekly.

Additional Active Agents

Additional veterinary/pharmaceutical active ingredients may be used withthe compositions of the invention. In some embodiments, the additionalactive agents may include, but are not limited to, acaricides,anthelmintics, anti-parasitics and insecticides. Anti-parasitic agentscan include both ectoparasiticidal and endoparasiticidal agents.

Veterinary pharmaceutical agents that may be included in thecompositions of the invention are well-known in the art (see e.g. Plumb'Veterinary Drug Handbook, 5^(th) Edition, ed. Donald C. Plumb, BlackwellPublishing, (2005) or The Merck Veterinary Manual, 9^(th) Edition,(January 2005)) and include but are not limited to acarbose,acepromazine maleate, acetaminophen, acetazolamide, acetazolamidesodium, acetic acid, acetohydroxamic acid, acetylcysteine, acitretin,acyclovir, albuterol sulfate, alfentanil, allopurinol, alprazolam,altrenogest, amantadine, amikacin sulfate, aminocaproic acid,aminopentamide hydrogen sulfate, aminophylline/theophylline, amiodarone,amitriptyline, amlodipine besylate, ammonium chloride, ammoniummolybdenate, amoxicillin, clavulanate potassium, amphotericin Bdesoxycholate, amphotericin B lipid-based, ampicillin, amprolium,antacids (oral), antivenin, apomorphione, apramycin sulfate, ascorbicacid, asparaginase, aspiring, atenolol, atipamezole, atracuriumbesylate, atropine sulfate, aurnofin, aurothioglucose, azaperone,azathioprine, azithromycin, baclofen, barbituates, benazepril,betamethasone, bethanechol chloride, bisacodyl, bismuth subsalicylate,bleomycin sulfate, boldenone undecylenate, bromides, bromocriptinemesylate, budenoside, buprenorphine, buspirone, busulfan, butorphanoltartrate, cabergoline, calcitonin salmon, calcitrol, calcium salts,captopril, carbenicillin indanyl sodium, carbimazole, carboplatin,carnitine, carprofen, carvedilol, cefadroxil, cefazolin sodium,cefixime, clorsulon, cefoperazone sodium, cefotaxime sodium, cefotetandisodium, cefoxitin sodium, cefpodoxime proxetil, ceftazidime, ceftiofursodium, ceftiofur, ceftiaxone sodium, cephalexin, cephalosporins,cephapirin, charcoal (activated), chlorambucil, chloramphenicol,chlordiazepoxide, chlordiazepoxide+/−clidinium bromide, chlorothiazide,chlorpheniramine maleate, chlorpromazine, chlorpropamide,chlortetracycline, chorionic gonadotropin (HCG), chromium, cimetidine,ciprofloxacin, cisapride, cisplatin, citrate salts, clarithromycin,clemastine fumarate, clenbuterol, clindamycin, clofazimine,clomipramine, claonazepam, clonidine, cloprostenol sodium, clorazepatedipotassium, cloxacillin, codeine phosphate, colchicine, corticotropin(ACTH), cosyntropin, cyclophosphamide, cyclosporine, cyproheptadine,cytarabine, dacarbazine, dactinomycin/actinomycin D, dalteparin sodium,danazol, dantrolene sodium, dapsone, decoquinate, deferoxamine mesylate,deracoxib, deslorelin acetate, desmopressin acetate,desoxycorticosterone pivalate, detomidine, dexamethasone, dexpanthenol,dexraazoxane, dextran, diazepam, diazoxide (oral), dichlorphenamide,diclofenac sodium, dicloxacillin, diethylcarbamazine citrate,diethylstilbestrol (DES), difloxacin, digoxin, dihydrotachysterol (DHT),diltiazem, dimenhydrinate, dimercaprol/BAL, dimethyl sulfoxide,dinoprost tromethamine, diphenylhydramine, disopyramide phosphate,dobutamine, docusate/DSS, dolasetron mesylate, domperidone, dopamine,doramectin, doxapram, doxepin, doxorubicin, doxycycline, edetate calciumdisodium, calcium EDTA, edrophonium chloride, enalapril/enalaprilat,enoxaparin sodium, enrofloxacin, ephedrine sulfate, epinephrine,epoetin/erythropoietin, eprinomectin, epsiprantel, erythromycin,esmolol, estradiol cypionate, ethacrynic acid/ethacrynate sodium,ethanol (alcohol), etidronate sodium, etodolac, etomidate, euthanasiaagents w/pentobarbital, famotidine, fatty acids (essential/omega),felbamate, fentanyl, ferrous sulfate, filgrastim, finasteride, fipronil,florfenicol, fluconazole, flucytosine, fludrocortisone acetate,flumazenil, flumethasone, flunixin meglumine, fluorouracil (5-FU),fluoxetine, fluticasone propionate, fluvoxamine maleate, fomepizole(4-MP), furazolidone, furosemide, gabapentin, gemcitabine, gentamicinsulfate, glimepiride, glipizide, glucagon, glucocorticoid agents,glucosamine/chondroitin sulfate, glutamine, glyburide, glycerine (oral),glycopyrrolate, gonadorelin, grisseofulvin, guaifenesin, halothane,hemoglobin glutamer-200 (OXYGLOBIN®), heparin, hetastarch, hyaluronatesodium, hydrazaline, hydrochlorothiazide, hydrocodone bitartrate,hydrocortisone, hydromorphone, hydroxyurea, hydroxyzine, ifosfamide,imidacloprid, imidocarb dipropinate, impenem-cilastatin sodium,imipramine, inamrinone lactate, insulin, interferon alfa-2a (humanrecombinant), iodide (sodium/potassium), ipecac (syrup), ipodate sodium,iron dextran, isoflurane, isoproterenol, isotretinoin, isoxsuprine,itraconazole, ivermectin, kaolin/pectin, ketamine, ketoconazole,ketoprofen, ketorolac tromethamine, lactulose, leuprolide,levetiracetam, levothyroxine sodium, lidocaine, lincomycin, liothyroninesodium, lisinopril, lomustine (CCNU), lysine, magnesium, mannitol,marbofloxacin, mechlorethamine, meclizine, meclofenamic acid,medetomidine, medium chain triglycerides, medroxyprogesterone acetate,megestrol acetate, melarsomine, melatonin, meloxican, melphalan,meperidine, mercaptopurine, meropenem, metformin, methadone,methazolamide, methenamine mandelate/hippurate, methimazole, methionine,methocarbamol, methohexital sodium, methotrexate, methoxyflurane,methylene blue, methylphenidate, methylprednisolone, metoclopramide,metoprolol, metronidaxole, mexiletine, mibolerlone, midazolam mineraloil, minocycline, misoprostol, mitotane, mitoxantrone, morphine sulfate,moxidectin, naloxone, mandrolone decanoate, naproxen, narcotic (opiate)agonist analgesics, neomycin sulfate, neostigmine, niacinamide,nitazoxanide, nitenpyram, nitrofurantoin, nitroglycerin, nitroprussidesodium, nizatidine, novobiocin sodium, nystatin, octreotide acetate,olsalazine sodium, omeprozole, ondansetron, opiate antidiarrheals,orbifloxacin, oxacillin sodium, oxazepam, oxibutynin chloride,oxymorphone, oxytretracycline, oxytocin, pamidronate disodium,pancreplipase, pancuronium bromide, paromomycin sulfate, parozetine,pencillamine, general information penicillins, penicillin G, penicillinV potassium, pentazocine, pentobarbital sodium, pentosan polysulfatesodium, pentoxifylline, pergolide mesylate, phenobarbital,phenoxybenzamine, pheylbutazone, phenylephrine, phenypropanolamine,phenytoin sodium, pheromones, parenteral phosphate, phytonadione/vitaminK-1, pimobendan, piperazine, pirlimycin, piroxicam, polysulfatedglycosaminoglycan, ponazuril, potassium chloride, pralidoxime chloride,prazosin, prednisolone/prednisone, primidone, procainamide,procarbazine, prochlorperazine, propantheline bromide, Propionibacteriumacnes injection, propofol, propranolol, protamine sulfate,pseudoephedrine, psyllium hydrophilic mucilloid, pyridostigmine bromide,pyrilamine maleate, pyrimethamine, quinacrine, quinidine, ranitidine,rifampin, s-adenosyl-methionine (SAMe), saline/hyperosmotic laxative,selamectin, selegiline/l-deprenyl, sertraline, sevelamer, sevoflurane,silymarin/milk thistle, sodium bicarbonate, sodium polystyrenesulfonate, sodium stibogluconate, sodium sulfate, sodum thiosulfate,somatotropin, sotalol, spectinomycin, spironolactone, stanozolol,streptokinase, streptozocin, succimer, succinylcholine chloride,sucralfate, sufentanil citrate, sulfachlorpyridazine sodium,sulfadiazine/trimethroprim, sulfamethoxazole/trimethoprim,sulfadimentoxine, sulfadimethoxine/ormetoprim, sulfasalazine, taurine,tepoxaline, terbinafline, terbutaline sulfate, testosterone,tetracycline, thiacetarsamide sodium, thiamine, thioguanine, thiopentalsodium, thiotepa, thyrotropin, tiamulin, ticarcilin disodium,tiletamine/zolazepam, tilmocsin, tiopronin, tobramycin sulfate,tocainide, tolazoline, telfenamic acid, topiramate, tramadol,trimcinolone acetonide, trientine, trilostane, trimepraxine tartratew/prednisolone, tripelennamine, tylosin, urdosiol, valproic acid,vanadium, vancomycin, vasopressin, vecuronium bromide, verapamil,vinblastine sulfate, vincristine sulfate, vitamin E/selenium, warfarinsodium, xylazine, yohimbine, zafirlukast, zidovudine (AZT), zincacetate/zinc sulfate, zonisamide and mixtures thereof.

In yet another embodiment of the invention, additional adulticideinsecticides and acaricides can also be added to the composition of theinvention. These include pyrethrins (which include cinerin I, cinerinII, jasmolin I, jasmolin II, pyrethrin I, pyrethrin II and mixturesthereof) and pyrethroids, and carbamates (which include but are notlimited to benomyl, carbanolate, carbaryl, carbofuran, meththiocarb,metolcarb, promacyl, propoxur, aldicarb, butocarboxim, oxamyl,thiocarboxime and thiofanox).

Suitable organophosphate active agents include, but are not limited to,coumaphos, trichlorfon, haloxon, naftalofos and dichlorvos, heptenophos,mevinphos, monocrotophos, TEPP, tetrachlorvinphos, and arylpyrazoles,e.g., fipronil.

In another embodiment of the invention, nodulisporic acid and itsderivatives (a class of known acaricidal, anthelmintic, anti-parasiticand insecticidal agents) may be included in the compositions of theinvention. These compounds are used to treat or prevent infections inhumans and animals and are described, for example, in U.S. Pat. Nos.5,399,582, 5,962,499, 6,221,894 and 6,399,786, all of which are herebyincorporated by reference in their entirety. The compositions mayinclude one or more of the known nodulisporic acid derivatives in theart, including all stereoisomers, such as those described in theliterature cited above.

In yet other embodiments, the compositions of the invention may includeother active agents that are effective against arthropod parasites.Suitable active agents include, but are not limited to, bromocyclen,chlordane, DDT, endosulfan, lindane, methoxychlor, toxaphene, bromophos,bromophos-ethyl, carbophenothion, chlorfenvinphos, chlorpyrifos,crotoxyphos, cythioate, diazinon, dichlorenthion, diemthoate,dioxathion, ethion, famphur, fenitrothion, fenthion, fospirate,iodofenphos, malathion, naled, phosalone, phosmet, phoxim, propetamphos,ronnel, stirofos, allethrin, cyhalothrin, cypermethrin, deltamethrin,fenvalerate, flucythrinate, permethrin, phenothrin, pyrethrins,resmethrin, benzyl benzoate, carbon disulfide, crotamiton,diflubenzuron, diphenylamine, disulfiram, isobornyl thiocyanato acetate,monosulfiram, pirenonylbutoxide, rotenone, triphenyltin acetate,triphenyltin hydroxide, deet, dimethyl phthalate, and the compounds1,5a,6,9,9a,9b-hexahydro-4a(4H)-dibenzofurancarboxaldehyde (MGK-11),2-(2-ethylhexyl)-3a,4,7,7a-tetrahydro-4,7-methano-1H-isoindole-1,3(2H)dione (MGK-264), dipropyl-2,5-pyridinedicarboxylate (MGK-326) and2-(octylthio)ethanol (MGK-874).

In another embodiment, the compositions of the invention mayadvantageously include one or more compounds of the isoxazoline class ofcompounds. These active agents are described in WO 2007/079162, WO2007/075459 and US 2009/0133319, WO 2007/070606 and US 2009/0143410, WO2009/003075, WO 2009/002809, WO 2009/024541, WO 2005/085216, U.S. Pat.Nos. 8,466,115, 8,853,186, 8,383,659 and US 2007/0066617 and WO2008/122375, all of which are incorporated herein by reference in theirentirety.

An insecticidal agent that can be combined with the compound of theinvention to form a composition can be a substituted pyridylmethylderivative compound such as imidacloprid. Agents of this class aredescribed above, and for example, in U.S. Pat. No. 4,742,060 or in EP 0892 060. It would be well within the skill level of the practitioner todecide which individual compound can be used in the inventiveformulation to treat a particular infection of an insect.

In certain embodiments, an insecticidal agent that can be combined withthe compositions of the invention is a semicarbazone, such asmetaflumizone.

In general, the additional active agent is included in the compositionin an amount of between about 0.1 μg and about 1000 mg. More typically,the additional active agent may be included in a dose of about 10 μg toabout 500 mg, about 1 mg to about 300 mg, about 10 mg to about 200 mg orabout 10 mg to about 100 mg. In one embodiment of the invention, theadditional active agent is included in a dose of between about 1 μg andabout 10 mg. In other embodiments of the invention, the additionalactive agent may be included in a dose of about 5 μg/kg to about 50mg/kg per weight of the animal. In other embodiments, the additionalactive agent may be present in a dose of about 0.01 mg/kg to about 30mg/kg, about 0.1 mg/kg to about 20 mg/kg, or about 0.1 mg/kg to about 10mg/kg of weight of animal. In other embodiments, the additional activeagent may be present in a dose of about 5 μg/kg to about 200 μg/kg orabout 0.1 mg/kg to about 1 mg/kg of weight of animal. In still anotherembodiment of the invention, the additional active agent is included ina dose between about 0.5 mg/kg to about 50 mg/kg.

Optionally, a fragrance may be added to any of the compositions of theinvention. Fragrances which are useful for the invention include but arenot limited to:

(i) carboxylic acid esters such as octyl acetate, isoamyl acetate,isopropyl acetate and isobutyl acetate;

(ii) fragrant oils such as lavender oil.

The compositions of the invention are made by mixing the appropriateamount of the active agents, pharmaceutically acceptable carrier ordiluent and optionally a crystallization inhibitor, antioxidant,preservative, film former, etc., to form a composition of the invention.Various forms (e.g. tablets, pastes, pour-on, spot-on, collars, etc.) ofthe composition can be obtained by following the method of making theseforms described above by the description of making these forms found ingeneral formulation text known to those in the art, e.g. Remington—TheScience and Practice of Pharmacy (21^(st) Edition) (2005), Goodman &Gilman's The Pharmacological Basis of Therapeutics (11^(th) Edition)(2005) and Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems(8^(th) Edition), edited by Allen et al., Lippincott Williams & Wilkins,(2005).

The inventive formulations may contain other inert ingredients such asantioxidants, preservatives, or pH stabilizers. These compounds are wellknown in the formulation art. Antioxidant such as an alpha tocopherol,ascorbic acid, ascrobyl palmitate, fumaric acid, malic acid, sodiumascorbate, sodium metabisulfate, n-propyl gallate, BHA (butylatedhydroxy anisole), BHT (butylated hydroxy toluene) monothioglycerol andthe like, may be added to the present formulation. The antioxidants aregenerally added to the formulation in amounts of from about 0.01 toabout 2.0% (w/v), with about 0.05 to about 1.0% (w/v) being especiallypreferred, and about 0.10% (w/v) being most preferred. In someembodiments, the formulations contain an antioxidant. In one embodiment,the antioxidant is BHT. In another embodiment, the antioxidant is BHA.

Preservatives, such as the parabens (methylparaben and/orpropylparaben), are suitably used in the formulation in amounts rangingfrom about 0.01 to about 2.0%, with about 0.05 to about 1.0% beingespecially preferred. Other preservatives include benzalkonium chloride,benzethonium chloride, benzoic acid, benzyl alcohol, bronopol,butylparaben, cetrimide, chlorhexidine, chlorobutanol, chlorocresol,cresol, ethylparaben, imidurea, methylparaben, phenol, phenoxyethanol,phenylethyl alcohol, phenylmercuric acetate, phenylmercuric borate,phenylmercuric nitrate, potassium sorbate, sodium benzoate, sodiumpropionate, sorbic acid, thimerosal, and the like. Preferred ranges forthese compounds include from about 0.01 to about 5%.

Compounds which stabilize the pH of the formulation are alsocontemplated. Again, such compounds are well known to a practitioner inthe art as well as how to use these compounds. Buffering systemsinclude, for example, systems selected from the group consisting ofacetic acid/acetate, malic acid/malate, citric acid/citrate, tataricacid/tartrate, lactic acid/lactate, phosphoric acid/phosphate,glycine/glycimate, tris, glutamic acid/glutamates and sodium carbonate.

The compositions of the invention are administered in parasiticidallyeffective amounts which are determined by the route of administration,e.g. oral, parenteral, topical, etc. In each aspect of the invention,the compounds and compositions of the invention can be applied against asingle pest or combinations thereof.

The compositions of the invention may be administered continuously, fortreatment or prevention of parasitic infections or infestations. In thismanner, the compositions of the invention deliver an effective amount ofthe active compounds to the animal in need thereof to control the targetparasites. By “effective amount” is intended a sufficient amount of acomposition of the invention to eradicate or reduce the number ofparasites infesting the animal. In some embodiments, an effective amountof the active agent achieves at least 70% efficacy against the targetparasite. In other embodiments, an effective amount of the active agentachieves at least 80%, or at least 90% efficacy against the targetpests. Preferably, an effective amount of the active agent will achieveat least 95%, at least 98% or 100% efficacy against the targetparasites.

Generally, a dose of from about 0.001 to about 100 mg per kg of bodyweight given as a single dose or in divided doses for a period of from 1to 5 days will be satisfactory but, of course, there can be instanceswhere higher or lower dosage ranges are indicated, and such are withinthe scope of this invention. It is well within the routine skill of thepractitioner to determine a particular dosing regimen for a specifichost and parasite.

In one treatment embodiment, the treatment is carried out so as toadminister to the animal, on a single occasion, a dose containingbetween about 0.001 and about 100 mg/kg of the active agents. In anotherembodiment, the composition administered delivers a dose of about 0.01to 5 mg/kg of a macrocyclic lactone active agent and about 1 to 20 mg/kgof an anthelmintic compound. In another embodiment, the compositions ofthe invention will deliver about 0.1 to 1 mg/kg of a macrocyclic lactoneand about 5 to about 15 mg/kg of an anthelmintic compound. In anotherembodiment, the compositions of the invention will deliver about 0.5mg/kg of a macrocyclic lactone and about 10 mg/kg of an anthelminticcompound. In yet another embodiment, the macrocyclic lactone activeagent is eprinomectin and the anthelmintic compound is praziquantel.

Higher amounts may be provided for very prolonged release in or on thebody of the animal. In another treatment embodiment, the amount ofactive agents for birds and other animals which are small in size isgreater than about 0.01 mg/kg, and in another embodiment for thetreatment of small-sized birds and other animals, the amount of isbetween about 0.01 and about 20 mg/kg of weight of animal.

The solutions according to the invention may be applied using any meansknown per se, e.g. using an applicator gun or a metering flask, pipette,syringes, roll on, droppers, capsules, foil packages, vials, twist tipcontainers and other single dose and multi-dose containers,

In yet another embodiment for the treatment of cats, a composition ofthe invention comprising or consisting essentially of a macrocycliclactone and an anthelmintic compound has an efficacy of at least about70%, 80%, 85%, 90%, 95% or 100% against endoparasites includingDipylidium caninum and Taenia taeniaeformis. In another embodiment forthe treatment of cats, a composition of the invention has an efficacy ofabout 70%, 80%, 85%, at least 90%, at least 95% or 100% against Taeniataeniaeformis. In another embodiment for the treatment of cats, acomposition of the invention has an efficacy of about 70%, 80%, 85%, atleast 90%, at least 95% or 100% against Echinococcus multilocularis. Inone embodiment, the macrocyclic lactone is eprinomectin and theanthelmintic compound is praziquantel.

In another embodiment for the treatment of cats, a compositioncomprising or consisting essentially of eprinomectin and praziquantelhas an efficacy of greater than about 95%, greater than about 97% orgreater than about 99% against adult Dipylidium caninum wherein theefficacy is statistically significant with a p<0.008.

In another embodiment for the treatment of cats, a compositioncomprising or consisting essentially of eprinomectin and praziquantelhas an efficacy of 100% against adult Echinococcus multiloculariswherein the efficacy is statistically significant with a p<0.001.

In another embodiment for the treatment of cats, a compositioncomprising or consisting essentially of a macrocyclic lactone and ananthelmintic compound has an efficacy of at least about 70%, 80%, 85%,at least 90%, at least 95% or 100% against Toxocara cati (roundworm). Inone embodiment, the macrocyclic lactone is eprinomectin and theanthelmintic compound is praziquantel. In another embodiment for thetreatment of cats, a composition comprising or consisting essentially ofeprinomectin and praziquantel has an efficacy of greater than about 98%or greater than about 99% against Toxocara cati wherein the efficacy isstatistically significant with a p<0.001. In yet another embodiment forthe treatment of cats, a composition comprising or consistingessentially of eprinomectin and praziquantel has an efficacy of greaterthan about 98% or greater than about 99% against the L4 Luminal larvaestage of Toxocara cati wherein the efficacy is statistically significantwith a p<0.001.

In another embodiment for the treatment of cats, a composition of theinvention comprising or consisting essentially of a macrocyclic lactoneand an anthelmintic compound has an efficacy of at least about 70%, 80%,85%, at least 90%, at least 95% or 100% against Ancylostoma tubaeformeAncylostoma braziliense (hookworm). In one embodiment, the macrocycliclactone is eprinomectin and the anthelmintic compound is praziquantel.In another embodiment for the treatment of cats, a compositioncomprising or consisting essentially of eprinomectin and praziquantelhas an efficacy of greater than about 98% or greater than about 99%against Ancylostoma tubaeforme or Ancylostoma braziliense wherein theefficacy is statistically significant with a p<0.001. In yet anotherembodiment for the treatment of cats, a composition comprising orconsisting essentially of eprinomectin and praziquantel has an efficacyof greater than about 85%, greater than about 90%, greater than about95% or greater than about 99% against the L4 larvae stage of Ancylostomatubaeforme wherein the efficacy is statistically significant with ap<0.001. In yet another embodiment for the treatment of cats, acomposition comprising or consisting essentially of eprinomectin andpraziquantel has an efficacy of 100% against the L4 larvae stage ofAncylostoma tubaeforme wherein the efficacy is statistically significantwith a p<0.001.

In another embodiment for the treatment of cats, a composition of theinvention comprising or consisting essentially of a macrocyclic lactoneand an anthelmintic compound has an efficacy of 100% against Dirofilariaimmitis (heartworm). In one embodiment, the macrocyclic lactone iseprinomectin and the anthelmintic compound is praziquantel. In anotherembodiment for the treatment of cats, a composition of the inventioncomprising or consisting essentially of eprinomectin and praziquantel isfound to have an efficacy of 100% against different isolates ofDirofilaria immitis (heartworm) from the U.S. and Europe.

In another embodiment for the treatment of cats, a composition of theinvention comprising or consisting essentially of a macrocyclic lactoneand an anthelmintic compound has proven safe for use in cats with adultDirofilaria immitis (heartworm) infection. In one embodiment, themacrocyclic lactone is eprinomectin and the anthelmintic compound ispraziquantel.

In one embodiment of the location of administration, a singleformulation containing the active agent in a substantially liquidcarrier and in a form which makes possible a single application, or anapplication repeated a small number of times, will be administered tothe animal over a localized region of the animal, e.g. between the twoshoulders. In one embodiment of the invention, the localized region hasa surface area of about 10 cm² or larger. In another embodiment of theinvention, the localized region has a surface are of between about 5 andabout 10 cm² area.

EXAMPLES

The invention is further described by the following non-limitingexamples which further illustrate the invention, and are not intended,nor should they be interpreted to, limit the scope of the invention.

Example 1: Exemplified Formulation

A composition of the present invention was formulated as a topicalformulation with the specifics shown below in Table 1.

Concentration Concentration Ingredient (% w/v) (% w/w) FunctionPraziquantel 8.300 7.032 Active Ingredient Eprinomectin 0.4000 0.3389Active Ingredient BHT, NF 0.1000 0.08472 Antioxidant Glycerol Formal30.38 25.74 Solvent (unstabilized) DMI QS 66.81 (QS) Solvent RelativeDensity at 20° C. = 1.1803Relative Density at 20° C.=1.1803

Example 2: Efficacy Against Endoparasites

The efficacy of topical compositions comprising eprinomectin andpraziquantel in a pharmaceutically acceptable carrier (mixture ofglycerol formal and dimethyl isosorbide) against endoparasites isstudied at different concentrations to deliver different doses ofeprinomectin and praziquantel.

Cats are infected with infective materials (eggs, larvae) of the targetparasite before treatment. Cats are screened and selected for the studybased on positive target parasite diagnosis (e.g. egg identification infeces). Alternatively, cats positive for the target parasite are sourcedand confirmed to be infected with the parasite (e.g. egg identificationin feces). On day 0, cats are treated with the composition tested,except for the control group. On approximately day 7-10 (time necessaryfor parasite to die and to be eliminated from the body), cats arenecropsied for parasite recovery and count. The efficacy or percentagereduction of the treatment is calculated by comparing the mean number oflive target parasites in the treated group with the mean number of livetarget parasites in the control group.

Compositions comprising praziquantel to deliver doses of 6, 8 or 10mg/kg are tested against Dipylidium caninum in 3 studies. The efficacyof compositions comprising praziquantel is tested against T.taeniaeformis and T. cati at certain doses. The data shows that at adose of 10 mg/kg praziquantel and 2.5 mg/kg eprinomectin, there is a92-100% reduction in the number of live Dipylidium caninum and T.taeniaeformis. At a dose of 10 mg/kg praziquantel and 0.25 mg/kgeprinomectin, there is a 95-100% reduction in the number of liveDipylidium caninum and T call.

Example 3: Effect of Eprinomectin Dose Against Endoparasites

In 12 separate studies, the effectiveness of compositions comprisingpraziquantel and varying doses of eprinomectin against variousendoparasites is studied. The compositions contain a concentration ofpraziquantel to deliver a dose of 10 mg/kg. The concentration ofeprinomectin was can be varied to deliver doses of between 0.1 mg/kg to10 mg/kg. Cats infected naturally or experimentally with A. tubaeforme(hookworm), T. cati (roundworm), D. caninum and different strains of D.immitis (heartworm) are used in the study. The results show that at adose of 0.2 mg/kg to 10 mg/kg eprinomectin, there is a 92-100% reductionin the number of live T. cati and a 98-100% reduction in the number oflive A. tubaeforme.

Example 4: Efficacy Against Endoparasites at 0.5 mg/kg Eprinomectin and10 mg/kg Praziquantel

The efficacy of topical formulation in Example 1 comprising eprinomectinand praziquantel in a pharmaceutically acceptable carrier (mixture ofglycerol formal and dimethyl isosorbide) against endoparasites isstudied at a dose of 0.5 mg/kg eprinomectin and 10 mg/kg praziquantel.

Cats are infected with infective materials (eggs, larvae) of the targetparasite before treatment. Cats are screened and selected for the studybased on positive target parasite diagnosis (e.g. egg identification infeces). Alternatively, cats positive for the target parasite are sourcedand confirmed to be infected with the parasite (e.g. egg identificationin feces). On day 0, cats are treated with the composition tested,except for the control group. On approximately day 7-10 (time necessaryfor parasite to die and to be eliminated from the body), cats arenecropsied for parasite recovery and count. The efficacy or percentagereduction of the treatment is calculated by comparing the mean number oflive target parasites in the treated group with the mean number of livetarget parasites in the control group.

The formulation of Example 1 at 0.5 mg/kg eprinomectin and 10 mg/kgpraziquantel is tested against Dipylidium caninum, T. taeniaeformis andT. cati. The data shows a 92-100% reduction in the number of liveDipylidium caninum, T. cali and T. taeniaeformis.

Example 5: Stability Study of Cat Endoparasiticide (Eprinomectin 0.4%(w/v) and Praziquantel 8.3% (w/v) Topical Solution in the MarketContainer

This experiment demonstrates the superior stability exhibited by theformulation of Example 1. The stability of each active in a preferredcomposition of the invention comprising eprinomectin and praziquantel ina carrier comprising glycerol formal and dimethyl isosorbide wasevaluated at accelerated condition (30° C./65% Relative Humidity) usinghigh performance liquid chromatography (HPLC). The study demonstratedthat each active in the composition was stable in solution for up to atleast 18 months at 30° C./65% RH in the presence of each other.

Table 2 below shows the average % label claim of praziquantel andeprinomectin from two different HPLC runs at different time point inmonth, from 0 to 18 months.

Time point (month) 0 3 6 9 12 18 Praziquantel (% LC) 99.52 97.38 97.7498.44 98.36 97.04 Eprinomectin (% LC) 99.33 97.92 97.61 98.40 98.5096.48These data demonstrate the superior shelf-life of the inventiveformulation.

Example 6: Pharmacokinetic Assessment

The formulation of Example 1 was administered to cats and thedistribution of the two active agents was measured. The concentration ofeprinomectin and praziquantel in the blood of cats over time is depictedin FIG. 1 . After administration, the formulation spreads across theskin and the active agents are rapidly absorbed. The Cmax ofeprinomectin is reached in 24 hours and the Cmax of praziquantel isreached in 6 hours. The terminal half-life of praziquantel is measuredto be 3.08 days and the half-life of eprinomectin is measured to be 4.75days.

As the non-limiting examples above demonstrate, the stable, extendedshelf-life compositions of the invention comprising at least onemacrocyclic lactone and at least one anthelmintic compound show superiorlong lasting efficacy against both ectoparasites and endoparasites in amammal (e.g., a cat).

Having thus described in detail various embodiments of the presentinvention, it is to be understood that the invention defined by theabove paragraphs is not to be limited to particular details set forth inthe above description as many apparent variations thereof are possiblewithout departing from the spirit or scope of the present invention.

What is claimed is:
 1. A topical veterinary composition having anextended shelf-life for treating or preventing a parasitic infection orinfestation in an animal, the composition consisting of: (a) about 0.40%(w/v) eprinomectin; (b) about 8.30% (w/v) praziquantel; (c) about 0.10%(w/v) BHT; (d) about 30.38% (w/v) glycerol formal; and (e) QS dimethylisosorbide, wherein glycerol formal does not contain EDTA or2,6-di-tert-butyl-4-methylphenol; and wherein the composition has ashelf-life of at least 6 months.
 2. The topical veterinary compositionof claim 1, wherein the composition is in the form of a spot-on or apour-on formulation.
 3. A method for controlling parasites in an animalcomprising administering to the animal in need thereof an effectiveamount of the topical veterinary composition of claim
 1. 4. The methodof claim 3, wherein the parasite is an endoparasite.
 5. The method ofclaim 4, wherein the endoparasite comprises cestodes, nematodes, and/ortrematodes.
 6. A method for the treatment or prevention of a parasiticinfection in an animal comprising administering to the animal in needthereof an effective amount of the topical veterinary composition ofclaim 1, wherein the parasitic infection is caused by a parasiteselected from the group consisting of Dirofilaria immitis, Dipylidiumcaninum, Taenia cali, Taenia taeniaeformis and Ancylostoma tubaeforme.